diff --git a/server/auth.js b/server/auth.js
index c476ea1e3..ea1e55e27 100644
--- a/server/auth.js
+++ b/server/auth.js
@@ -2,7 +2,6 @@ const basicAuth = require("express-basic-auth");
 const passwordHash = require("./password-hash");
 const { R } = require("redbean-node");
 const { setting } = require("./util-server");
-const { debug } = require("../src/util");
 const { loginRateLimiter } = require("./rate-limiter");
 
 /**
diff --git a/server/database.js b/server/database.js
index 41d91e858..53fd3ef96 100644
--- a/server/database.js
+++ b/server/database.js
@@ -1,7 +1,7 @@
 const fs = require("fs");
 const { R } = require("redbean-node");
 const { setSetting, setting } = require("./util-server");
-const { debug, sleep } = require("../src/util");
+const { log, sleep } = require("../src/util");
 const dayjs = require("dayjs");
 const knex = require("knex");
 
@@ -76,7 +76,7 @@ class Database {
             fs.mkdirSync(Database.uploadDir, { recursive: true });
         }
 
-        console.log(`Data Dir: ${Database.dataDir}`);
+        log("db", `Data Dir: ${Database.dataDir}`);
     }
 
     static async connect() {
@@ -117,10 +117,10 @@ class Database {
         await R.exec("PRAGMA cache_size = -12000");
         await R.exec("PRAGMA auto_vacuum = FULL");
 
-        console.log("SQLite config:");
-        console.log(await R.getAll("PRAGMA journal_mode"));
-        console.log(await R.getAll("PRAGMA cache_size"));
-        console.log("SQLite Version: " + await R.getCell("SELECT sqlite_version()"));
+        log("db", "SQLite config:");
+        log("db", await R.getAll("PRAGMA journal_mode"));
+        log("db", await R.getAll("PRAGMA cache_size"));
+        log("db","SQLite Version: " + await R.getCell("SELECT sqlite_version()"));
     }
 
     static async patch() {
@@ -130,15 +130,15 @@ class Database {
             version = 0;
         }
 
-        console.info("Your database version: " + version);
-        console.info("Latest database version: " + this.latestVersion);
+        log("db", "Your database version: " + version);
+        log("db", "Latest database version: " + this.latestVersion);
 
         if (version === this.latestVersion) {
-            console.info("Database patch not needed");
+            log("db", "Database patch not needed");
         } else if (version > this.latestVersion) {
-            console.info("Warning: Database version is newer than expected");
+            log("db", "Warning: Database version is newer than expected");
         } else {
-            console.info("Database patch is needed");
+            log("db", "Database patch is needed");
 
             this.backup(version);
 
@@ -146,17 +146,17 @@ class Database {
             try {
                 for (let i = version + 1; i <= this.latestVersion; i++) {
                     const sqlFile = `./db/patch${i}.sql`;
-                    console.info(`Patching ${sqlFile}`);
+                    log("db", `Patching ${sqlFile}`);
                     await Database.importSQLFile(sqlFile);
-                    console.info(`Patched ${sqlFile}`);
+                    log("db", `Patched ${sqlFile}`);
                     await setSetting("database_version", i);
                 }
             } catch (ex) {
                 await Database.close();
 
-                console.error(ex);
-                console.error("Start Uptime-Kuma failed due to issue patching the database");
-                console.error("Please submit a bug report if you still encounter the problem after restart: https://github.com/louislam/uptime-kuma/issues");
+                log("db", ex, "error");
+                log("db", "Start Uptime-Kuma failed due to issue patching the database", "error");
+                log("db", "Please submit a bug report if you still encounter the problem after restart: https://github.com/louislam/uptime-kuma/issues", "error");
 
                 this.restore();
                 process.exit(1);
@@ -171,15 +171,15 @@ class Database {
      * @returns {Promise<void>}
      */
     static async patch2() {
-        console.log("Database Patch 2.0 Process");
+        log("db", "Database Patch 2.0 Process");
         let databasePatchedFiles = await setting("databasePatchedFiles");
 
         if (! databasePatchedFiles) {
             databasePatchedFiles = {};
         }
 
-        debug("Patched files:");
-        debug(databasePatchedFiles);
+        log("db", "Patched files:", "debug");
+        log("db", databasePatchedFiles, "debug");
 
         try {
             for (let sqlFilename in this.patchList) {
@@ -187,15 +187,15 @@ class Database {
             }
 
             if (this.patched) {
-                console.log("Database Patched Successfully");
+                log("db", "Database Patched Successfully");
             }
 
         } catch (ex) {
             await Database.close();
 
-            console.error(ex);
-            console.error("Start Uptime-Kuma failed due to issue patching the database");
-            console.error("Please submit the bug report if you still encounter the problem after restart: https://github.com/louislam/uptime-kuma/issues");
+            log("db", ex, "error");
+            log("db", "Start Uptime-Kuma failed due to issue patching the database", "error");
+            log("db", "Please submit the bug report if you still encounter the problem after restart: https://github.com/louislam/uptime-kuma/issues", "error");
 
             this.restore();
 
@@ -214,16 +214,16 @@ class Database {
         let value = this.patchList[sqlFilename];
 
         if (! value) {
-            console.log(sqlFilename + " skip");
+            log("db", sqlFilename + " skip");
             return;
         }
 
         // Check if patched
         if (! databasePatchedFiles[sqlFilename]) {
-            console.log(sqlFilename + " is not patched");
+            log("db", sqlFilename + " is not patched");
 
             if (value.parents) {
-                console.log(sqlFilename + " need parents");
+                log("db", sqlFilename + " need parents");
                 for (let parentSQLFilename of value.parents) {
                     await this.patch2Recursion(parentSQLFilename, databasePatchedFiles);
                 }
@@ -231,14 +231,14 @@ class Database {
 
             this.backup(dayjs().format("YYYYMMDDHHmmss"));
 
-            console.log(sqlFilename + " is patching");
+            log("db", sqlFilename + " is patching");
             this.patched = true;
             await this.importSQLFile("./db/" + sqlFilename);
             databasePatchedFiles[sqlFilename] = true;
-            console.log(sqlFilename + " was patched successfully");
+            log("db", sqlFilename + " was patched successfully");
 
         } else {
-            debug(sqlFilename + " is already patched, skip");
+            log("db", sqlFilename + " is already patched, skip", "debug");
         }
     }
 
@@ -290,7 +290,7 @@ class Database {
         };
         process.addListener("unhandledRejection", listener);
 
-        console.log("Closing the database");
+        log("db", "Closing the database");
 
         while (true) {
             Database.noReject = true;
@@ -300,10 +300,10 @@ class Database {
             if (Database.noReject) {
                 break;
             } else {
-                console.log("Waiting to close the database");
+                log("db", "Waiting to close the database");
             }
         }
-        console.log("SQLite closed");
+        log("db", "SQLite closed");
 
         process.removeListener("unhandledRejection", listener);
     }
@@ -315,7 +315,7 @@ class Database {
      */
     static backup(version) {
         if (! this.backupPath) {
-            console.info("Backing up the database");
+            log("db", "Backing up the database");
             this.backupPath = this.dataDir + "kuma.db.bak" + version;
             fs.copyFileSync(Database.path, this.backupPath);
 
@@ -338,7 +338,7 @@ class Database {
      */
     static restore() {
         if (this.backupPath) {
-            console.error("Patching the database failed!!! Restoring the backup");
+            log("db", "Patching the database failed!!! Restoring the backup", "error");
 
             const shmPath = Database.path + "-shm";
             const walPath = Database.path + "-wal";
@@ -357,7 +357,7 @@ class Database {
                     fs.unlinkSync(walPath);
                 }
             } catch (e) {
-                console.log("Restore failed; you may need to restore the backup manually");
+                log("db", "Restore failed; you may need to restore the backup manually", "error");
                 process.exit(1);
             }
 
@@ -373,14 +373,14 @@ class Database {
             }
 
         } else {
-            console.log("Nothing to restore");
+            log("db", "Nothing to restore");
         }
     }
 
     static getSize() {
-        debug("Database.getSize()");
+        log("db", "Database.getSize()", "debug");
         let stats = fs.statSync(Database.path);
-        debug(stats);
+        log("db", stats, "debug");
         return stats.size;
     }
 
diff --git a/server/image-data-uri.js b/server/image-data-uri.js
index 3ccaab7d5..6aa4387ab 100644
--- a/server/image-data-uri.js
+++ b/server/image-data-uri.js
@@ -3,12 +3,13 @@
     Modified with 0 dependencies
  */
 let fs = require("fs");
+const { log } = require("../src/util");
 
 let ImageDataURI = (() => {
 
     function decode(dataURI) {
         if (!/data:image\//.test(dataURI)) {
-            console.log("ImageDataURI :: Error :: It seems that it is not an Image Data URI. Couldn't match \"data:image/\"");
+            log("image-data-uri", "It seems that it is not an Image Data URI. Couldn't match \"data:image/\"", "error");
             return null;
         }
 
@@ -22,7 +23,7 @@ let ImageDataURI = (() => {
 
     function encode(data, mediaType) {
         if (!data || !mediaType) {
-            console.log("ImageDataURI :: Error :: Missing some of the required params: data, mediaType ");
+            log("image-data-uri", "Missing some of the required params: data, mediaType", "error");
             return null;
         }
 
diff --git a/server/jobs.js b/server/jobs.js
index 0469d5cab..56a67b0fa 100644
--- a/server/jobs.js
+++ b/server/jobs.js
@@ -1,6 +1,7 @@
 const path = require("path");
 const Bree = require("bree");
 const { SHARE_ENV } = require("worker_threads");
+const { log } = require("../src/util");
 
 const jobs = [
     {
@@ -18,7 +19,7 @@ const initBackgroundJobs = function (args) {
             workerData: args,
         },
         workerMessageHandler: (message) => {
-            console.log("[Background Job]:", message);
+            log("jobs", message);
         }
     });
 
diff --git a/server/model/monitor.js b/server/model/monitor.js
index 980e0ac69..f7d17f292 100644
--- a/server/model/monitor.js
+++ b/server/model/monitor.js
@@ -6,7 +6,7 @@ dayjs.extend(utc);
 dayjs.extend(timezone);
 const axios = require("axios");
 const { Prometheus } = require("../prometheus");
-const { debug, UP, DOWN, PENDING, flipStatus, TimeLogger } = require("../../src/util");
+const { log, UP, DOWN, PENDING, flipStatus, TimeLogger } = require("../../src/util");
 const { tcping, ping, dnsResolve, checkCertificate, checkStatusCode, getTotalClientInRoom, setting, errorLog } = require("../util-server");
 const { R } = require("redbean-node");
 const { BeanModel } = require("redbean-node/dist/bean-model");
@@ -141,7 +141,7 @@ class Monitor extends BeanModel {
                     // Do not do any queries/high loading things before the "bean.ping"
                     let startTime = dayjs().valueOf();
 
-                    debug(`[${this.name}] Prepare Options for axios`);
+                    log("monitor", `[${this.name}] Prepare Options for axios`, "debug");
                     const options = {
                         url: this.url,
                         method: (this.method || "get").toLowerCase(),
@@ -162,7 +162,7 @@ class Monitor extends BeanModel {
                         },
                     };
 
-                    debug(`[${this.name}] Axios Request`);
+                    log("monitor", `[${this.name}] Axios Request`, "debug");
                     let res = await axios.request(options);
                     bean.msg = `${res.status} - ${res.statusText}`;
                     bean.ping = dayjs().valueOf() - startTime;
@@ -170,29 +170,30 @@ class Monitor extends BeanModel {
                     // Check certificate if https is used
                     let certInfoStartTime = dayjs().valueOf();
                     if (this.getUrl()?.protocol === "https:") {
-                        debug(`[${this.name}] Check cert`);
+                        log("monitor", `[${this.name}] Check cert`, "debug");
                         try {
                             let tlsInfoObject = checkCertificate(res);
                             tlsInfo = await this.updateTlsInfo(tlsInfoObject);
 
                             if (!this.getIgnoreTls()) {
-                                debug(`[${this.name}] call sendCertNotification`);
+                                log("monitor", `[${this.name}] call sendCertNotification`, "debug");
                                 await this.sendCertNotification(tlsInfoObject);
                             }
 
                         } catch (e) {
                             if (e.message !== "No TLS certificate in response") {
-                                console.error(e.message);
+                                log("monitor", "Caught error", "error");
+                                log("monitor", e.message, "error");
                             }
                         }
                     }
 
                     if (process.env.TIMELOGGER === "1") {
-                        debug("Cert Info Query Time: " + (dayjs().valueOf() - certInfoStartTime) + "ms");
+                        log("monitor", "Cert Info Query Time: " + (dayjs().valueOf() - certInfoStartTime) + "ms", "debug");
                     }
 
                     if (process.env.UPTIME_KUMA_LOG_RESPONSE_BODY_MONITOR_ID == this.id) {
-                        console.log(res.data);
+                        log("monitor", res.data);
                     }
 
                     if (this.type === "http") {
@@ -272,7 +273,7 @@ class Monitor extends BeanModel {
                         time
                     ]);
 
-                    debug("heartbeatCount" + heartbeatCount + " " + time);
+                    log("monitor", "heartbeatCount" + heartbeatCount + " " + time, "debug");
 
                     if (heartbeatCount <= 0) {
                         throw new Error("No heartbeat in the time window");
@@ -355,7 +356,7 @@ class Monitor extends BeanModel {
 
             let beatInterval = this.interval;
 
-            debug(`[${this.name}] Check isImportant`);
+            log("monitor", `[${this.name}] Check isImportant`, "debug");
             let isImportant = Monitor.isImportantBeat(isFirstBeat, previousBeat?.status, bean.status);
 
             // Mark as important if status changed, ignore pending pings,
@@ -363,11 +364,11 @@ class Monitor extends BeanModel {
             if (isImportant) {
                 bean.important = true;
 
-                debug(`[${this.name}] sendNotification`);
+                log("monitor", `[${this.name}] sendNotification`, "debug");
                 await Monitor.sendNotification(isFirstBeat, this, bean);
 
                 // Clear Status Page Cache
-                debug(`[${this.name}] apicache clear`);
+                log("monitor", `[${this.name}] apicache clear`, "debug");
                 apicache.clear();
 
             } else {
@@ -375,24 +376,24 @@ class Monitor extends BeanModel {
             }
 
             if (bean.status === UP) {
-                console.info(`Monitor #${this.id} '${this.name}': Successful Response: ${bean.ping} ms | Interval: ${beatInterval} seconds | Type: ${this.type}`);
+                log("monitor", `Monitor #${this.id} '${this.name}': Successful Response: ${bean.ping} ms | Interval: ${beatInterval} seconds | Type: ${this.type}`);
             } else if (bean.status === PENDING) {
                 if (this.retryInterval > 0) {
                     beatInterval = this.retryInterval;
                 }
-                console.warn(`Monitor #${this.id} '${this.name}': Pending: ${bean.msg} | Max retries: ${this.maxretries} | Retry: ${retries} | Retry Interval: ${beatInterval} seconds | Type: ${this.type}`);
+                log("monitor", `Monitor #${this.id} '${this.name}': Pending: ${bean.msg} | Max retries: ${this.maxretries} | Retry: ${retries} | Retry Interval: ${beatInterval} seconds | Type: ${this.type}`, "warn");
             } else {
-                console.warn(`Monitor #${this.id} '${this.name}': Failing: ${bean.msg} | Interval: ${beatInterval} seconds | Type: ${this.type}`);
+                log("monitor", `Monitor #${this.id} '${this.name}': Failing: ${bean.msg} | Interval: ${beatInterval} seconds | Type: ${this.type}`, "warn");
             }
 
-            debug(`[${this.name}] Send to socket`);
+            log("monitor", `[${this.name}] Send to socket`, "debug");
             io.to(this.user_id).emit("heartbeat", bean.toJSON());
             Monitor.sendStats(io, this.id, this.user_id);
 
-            debug(`[${this.name}] Store`);
+            log("monitor", `[${this.name}] Store`, "debug");
             await R.store(bean);
 
-            debug(`[${this.name}] prometheus.update`);
+            log("monitor", `[${this.name}] prometheus.update`, "debug");
             prometheus.update(bean, tlsInfo);
 
             previousBeat = bean;
@@ -401,15 +402,15 @@ class Monitor extends BeanModel {
 
                 if (demoMode) {
                     if (beatInterval < 20) {
-                        console.log("beat interval too low, reset to 20s");
+                        log("monitor", "beat interval too low, reset to 20s");
                         beatInterval = 20;
                     }
                 }
 
-                debug(`[${this.name}] SetTimeout for next check.`);
+                log("monitor", `[${this.name}] SetTimeout for next check.`, "debug");
                 this.heartbeatInterval = setTimeout(safeBeat, beatInterval * 1000);
             } else {
-                console.log(`[${this.name}] isStop = true, no next check.`);
+                log("monitor", `[${this.name}] isStop = true, no next check.`);
             }
 
         };
@@ -420,10 +421,10 @@ class Monitor extends BeanModel {
             } catch (e) {
                 console.trace(e);
                 errorLog(e, false);
-                console.error("Please report to https://github.com/louislam/uptime-kuma/issues");
+                log("monitor", "Please report to https://github.com/louislam/uptime-kuma/issues", "error");
 
                 if (! this.isStop) {
-                    console.log("Try to restart the monitor");
+                    log("monitor", "Try to restart the monitor");
                     this.heartbeatInterval = setTimeout(safeBeat, this.interval * 1000);
                 }
             }
@@ -481,17 +482,17 @@ class Monitor extends BeanModel {
 
                 if (isValidObjects) {
                     if (oldCertInfo.certInfo.fingerprint256 !== checkCertificateResult.certInfo.fingerprint256) {
-                        debug("Resetting sent_history");
+                        log("monitor", "Resetting sent_history", "debug");
                         await R.exec("DELETE FROM notification_sent_history WHERE type = 'certificate' AND monitor_id = ?", [
                             this.id
                         ]);
                     } else {
-                        debug("No need to reset sent_history");
-                        debug(oldCertInfo.certInfo.fingerprint256);
-                        debug(checkCertificateResult.certInfo.fingerprint256);
+                        log("monitor", "No need to reset sent_history", "debug");
+                        log("monitor", oldCertInfo.certInfo.fingerprint256, "debug");
+                        log("monitor", checkCertificateResult.certInfo.fingerprint256, "debug");
                     }
                 } else {
-                    debug("Not valid object");
+                    log("monitor", "Not valid object", "debug");
                 }
             } catch (e) { }
 
@@ -512,7 +513,7 @@ class Monitor extends BeanModel {
             await Monitor.sendUptime(24 * 30, io, monitorID, userID);
             await Monitor.sendCertInfo(io, monitorID, userID);
         } else {
-            debug("No clients in the room, no need to send stats");
+            log("monitor", "No clients in the room, no need to send stats", "debug");
         }
     }
 
@@ -659,8 +660,8 @@ class Monitor extends BeanModel {
                 try {
                     await Notification.send(JSON.parse(notification.config), msg, await monitor.toJSON(), bean.toJSON());
                 } catch (e) {
-                    console.error("Cannot send notification to " + notification.name);
-                    console.log(e);
+                    log("monitor", "Cannot send notification to " + notification.name, "error");
+                    log("monitor", e, "error");
                 }
             }
         }
@@ -677,7 +678,7 @@ class Monitor extends BeanModel {
         if (tlsInfoObject && tlsInfoObject.certInfo && tlsInfoObject.certInfo.daysRemaining) {
             const notificationList = await Monitor.getNotificationList(this);
 
-            debug("call sendCertNotificationByTargetDays");
+            log("monitor", "call sendCertNotificationByTargetDays", "debug");
             await this.sendCertNotificationByTargetDays(tlsInfoObject.certInfo.daysRemaining, 21, notificationList);
             await this.sendCertNotificationByTargetDays(tlsInfoObject.certInfo.daysRemaining, 14, notificationList);
             await this.sendCertNotificationByTargetDays(tlsInfoObject.certInfo.daysRemaining, 7, notificationList);
@@ -687,7 +688,7 @@ class Monitor extends BeanModel {
     async sendCertNotificationByTargetDays(daysRemaining, targetDays, notificationList) {
 
         if (daysRemaining > targetDays) {
-            debug(`No need to send cert notification. ${daysRemaining} > ${targetDays}`);
+            log("monitor", `No need to send cert notification. ${daysRemaining} > ${targetDays}`, "debug");
             return;
         }
 
@@ -701,21 +702,21 @@ class Monitor extends BeanModel {
 
             // Sent already, no need to send again
             if (row) {
-                debug("Sent already, no need to send again");
+                log("monitor", "Sent already, no need to send again", "debug");
                 return;
             }
 
             let sent = false;
-            debug("Send certificate notification");
+            log("monitor", "Send certificate notification", "debug");
 
             for (let notification of notificationList) {
                 try {
-                    debug("Sending to " + notification.name);
+                    log("monitor", "Sending to " + notification.name, "debug");
                     await Notification.send(JSON.parse(notification.config), `[${this.name}][${this.url}] Certificate will be expired in ${daysRemaining} days`);
                     sent = true;
                 } catch (e) {
-                    console.error("Cannot send cert notification to " + notification.name);
-                    console.error(e);
+                    log("monitor", "Cannot send cert notification to " + notification.name, "error");
+                    log("monitor", e, "error");
                 }
             }
 
@@ -727,7 +728,7 @@ class Monitor extends BeanModel {
                 ]);
             }
         } else {
-            debug("No notification, no need to send cert notification");
+            log("monitor", "No notification, no need to send cert notification", "debug");
         }
     }
 }
diff --git a/server/notification-providers/matrix.js b/server/notification-providers/matrix.js
index c1054fce6..1aaf56924 100644
--- a/server/notification-providers/matrix.js
+++ b/server/notification-providers/matrix.js
@@ -1,7 +1,7 @@
 const NotificationProvider = require("./notification-provider");
 const axios = require("axios");
 const Crypto = require("crypto");
-const { debug } = require("../../src/util");
+const { log } = require("../../src/util");
 
 class Matrix extends NotificationProvider {
     name = "matrix";
@@ -17,11 +17,11 @@ class Matrix extends NotificationProvider {
                 .slice(0, size)
         );
 
-        debug("Random String: " + randomString);
+        log("notification", "Random String: " + randomString, "debug");
 
         const roomId = encodeURIComponent(notification.internalRoomId);
 
-        debug("Matrix Room ID: " + roomId);
+        log("notification", "Matrix Room ID: " + roomId, "debug");
 
         try {
             let config = {
diff --git a/server/notification.js b/server/notification.js
index 18c823b2b..e0325759f 100644
--- a/server/notification.js
+++ b/server/notification.js
@@ -23,13 +23,14 @@ const Feishu = require("./notification-providers/feishu");
 const AliyunSms = require("./notification-providers/aliyun-sms");
 const DingDing = require("./notification-providers/dingding");
 const Bark = require("./notification-providers/bark");
+const { log } = require("../src/util");
 
 class Notification {
 
     providerList = {};
 
     static init() {
-        console.log("Prepare Notification Providers");
+        log("notification", "Prepare Notification Providers");
 
         this.providerList = {};
 
diff --git a/server/prometheus.js b/server/prometheus.js
index 870581d2e..e7e39881f 100644
--- a/server/prometheus.js
+++ b/server/prometheus.js
@@ -1,4 +1,5 @@
 const PrometheusClient = require("prom-client");
+const { log } = require("../src/util");
 
 const commonLabels = [
     "monitor_name",
@@ -56,20 +57,23 @@ class Prometheus {
                 }
                 monitor_cert_is_valid.set(this.monitorLabelValues, is_valid);
             } catch (e) {
-                console.error(e);
+                log("prometheus", "Caught error", "error");
+                log("prometheus", e, "error");
             }
 
             try {
                 monitor_cert_days_remaining.set(this.monitorLabelValues, tlsInfo.certInfo.daysRemaining);
             } catch (e) {
-                console.error(e);
+                log("prometheus", "Caught error", "error");
+                log("prometheus", e, "error");
             }
         }
 
         try {
             monitor_status.set(this.monitorLabelValues, heartbeat.status);
         } catch (e) {
-            console.error(e);
+            log("prometheus", "Caught error", "error");
+            log("prometheus", e, "error");
         }
 
         try {
@@ -80,7 +84,8 @@ class Prometheus {
                 monitor_response_time.set(this.monitorLabelValues, -1);
             }
         } catch (e) {
-            console.error(e);
+            log("prometheus", "Caught error", "error");
+            log("prometheus", e, "error");
         }
     }
 
diff --git a/server/rate-limiter.js b/server/rate-limiter.js
index 0bacc14c7..10db259da 100644
--- a/server/rate-limiter.js
+++ b/server/rate-limiter.js
@@ -1,5 +1,5 @@
 const { RateLimiter } = require("limiter");
-const { debug } = require("../src/util");
+const { log } = require("../src/util");
 
 class KumaRateLimiter {
     constructor(config) {
@@ -9,7 +9,7 @@ class KumaRateLimiter {
 
     async pass(callback, num = 1) {
         const remainingRequests = await this.removeTokens(num);
-        debug("Rate Limit (remainingRequests):" + remainingRequests);
+        log("rate-limit", "remaining requests: " + remainingRequests);
         if (remainingRequests < 0) {
             if (callback) {
                 callback({
diff --git a/server/routers/api-router.js b/server/routers/api-router.js
index 79e828378..2991e5cad 100644
--- a/server/routers/api-router.js
+++ b/server/routers/api-router.js
@@ -5,7 +5,7 @@ const server = require("../server");
 const apicache = require("../modules/apicache");
 const Monitor = require("../model/monitor");
 const dayjs = require("dayjs");
-const { UP, flipStatus, debug } = require("../../src/util");
+const { UP, flipStatus, log } = require("../../src/util");
 let router = express.Router();
 
 let cache = apicache.middleware;
@@ -56,8 +56,8 @@ router.get("/api/push/:pushToken", async (request, response) => {
             duration = dayjs(bean.time).diff(dayjs(previousHeartbeat.time), "second");
         }
 
-        debug("PreviousStatus: " + previousStatus);
-        debug("Current Status: " + status);
+        log("router", "PreviousStatus: " + previousStatus, "debug");
+        log("router", "Current Status: " + status, "debug");
 
         bean.important = Monitor.isImportantBeat(isFirstBeat, previousStatus, status);
         bean.monitor_id = monitor.id;
diff --git a/server/server.js b/server/server.js
index d1fd7ff29..e4cd56c1b 100644
--- a/server/server.js
+++ b/server/server.js
@@ -1,56 +1,57 @@
-console.log("Welcome to Uptime Kuma");
 const args = require("args-parser")(process.argv);
-const { sleep, debug, getRandomInt, genSecret } = require("../src/util");
+const { sleep, log, getRandomInt, genSecret } = require("../src/util");
 const config = require("./config");
 
-debug(args);
+log("server", "Welcome to Uptime Kuma");
+log("server", "Arguments", "debug");
+log("server", args, "debug");
 
 if (! process.env.NODE_ENV) {
     process.env.NODE_ENV = "production";
 }
 
-console.log("Node Env: " + process.env.NODE_ENV);
+log("server", "Node Env: " + process.env.NODE_ENV);
 
-console.log("Importing Node libraries");
+log("server", "Importing Node libraries");
 const fs = require("fs");
 const http = require("http");
 const https = require("https");
 
-console.log("Importing 3rd-party libraries");
-debug("Importing express");
+log("server", "Importing 3rd-party libraries");
+log("server", "Importing express", "debug");
 const express = require("express");
-debug("Importing socket.io");
+log("server", "Importing socket.io", "debug");
 const { Server } = require("socket.io");
-debug("Importing redbean-node");
+log("server", "Importing redbean-node", "debug");
 const { R } = require("redbean-node");
-debug("Importing jsonwebtoken");
+log("server", "Importing jsonwebtoken", "debug");
 const jwt = require("jsonwebtoken");
-debug("Importing http-graceful-shutdown");
+log("server", "Importing http-graceful-shutdown", "debug");
 const gracefulShutdown = require("http-graceful-shutdown");
-debug("Importing prometheus-api-metrics");
+log("server", "Importing prometheus-api-metrics", "debug");
 const prometheusAPIMetrics = require("prometheus-api-metrics");
-debug("Importing compare-versions");
+log("server", "Importing compare-versions", "debug");
 const compareVersions = require("compare-versions");
 const { passwordStrength } = require("check-password-strength");
 
-debug("Importing 2FA Modules");
+log("server", "Importing 2FA Modules", "debug");
 const notp = require("notp");
 const base32 = require("thirty-two");
 
-console.log("Importing this project modules");
-debug("Importing Monitor");
+log("server", "Importing this project modules");
+log("server", "Importing Monitor", "debug");
 const Monitor = require("./model/monitor");
-debug("Importing Settings");
+log("server", "Importing Settings", "debug");
 const { getSettings, setSettings, setting, initJWTSecret, checkLogin, startUnitTest, FBSD, errorLog } = require("./util-server");
 
-debug("Importing Notification");
+log("server", "Importing Notification", "debug");
 const { Notification } = require("./notification");
 Notification.init();
 
-debug("Importing Database");
+log("server", "Importing Database", "debug");
 const Database = require("./database");
 
-debug("Importing Background Jobs");
+log("server", "Importing Background Jobs", "debug");
 const { initBackgroundJobs } = require("./jobs");
 const { loginRateLimiter } = require("./rate-limiter");
 
@@ -59,7 +60,7 @@ const { login } = require("./auth");
 const passwordHash = require("./password-hash");
 
 const checkVersion = require("./check-version");
-console.info("Version: " + checkVersion.version);
+log("server", "Version: " + checkVersion.version);
 
 // If host is omitted, the server will accept connections on the unspecified IPv6 address (::) when IPv6 is available and the unspecified IPv4 address (0.0.0.0) otherwise.
 // Dual-stack support for (::)
@@ -71,7 +72,7 @@ if (!hostname && !FBSD) {
 }
 
 if (hostname) {
-    console.log("Custom hostname: " + hostname);
+    log("server", "Custom hostname: " + hostname);
 }
 
 const port = parseInt(process.env.UPTIME_KUMA_PORT || process.env.PORT || args.port || 3001);
@@ -94,22 +95,22 @@ const twofa_verification_opts = {
 const testMode = !!args["test"] || false;
 
 if (config.demoMode) {
-    console.log("==== Demo Mode ====");
+    log("server", "==== Demo Mode ====");
 }
 
-console.log("Creating express and socket.io instance");
+log("server", "Creating express and socket.io instance");
 const app = express();
 
 let server;
 
 if (sslKey && sslCert) {
-    console.log("Server Type: HTTPS");
+    log("server", "Server Type: HTTPS");
     server = https.createServer({
         key: fs.readFileSync(sslKey),
         cert: fs.readFileSync(sslCert)
     }, app);
 } else {
-    console.log("Server Type: HTTP");
+    log("server", "Server Type: HTTP");
     server = http.createServer(app);
 }
 
@@ -167,7 +168,7 @@ try {
 } catch (e) {
     // "dist/index.html" is not necessary for development
     if (process.env.NODE_ENV !== "development") {
-        console.error("Error: Cannot find 'dist/index.html', did you install correctly?");
+        log("server", "Error: Cannot find 'dist/index.html', did you install correctly?", "error");
         process.exit(1);
     }
 }
@@ -180,7 +181,7 @@ exports.entryPage = "dashboard";
 
     exports.entryPage = await setting("entryPage");
 
-    console.log("Adding route");
+    log("server", "Adding route");
 
     // ***************************
     // Normal Router here
@@ -233,7 +234,7 @@ exports.entryPage = "dashboard";
         }
     });
 
-    console.log("Adding socket handler");
+    log("server", "Adding socket handler");
     io.on("connection", async (socket) => {
 
         sendInfo(socket);
@@ -241,7 +242,7 @@ exports.entryPage = "dashboard";
         totalClient++;
 
         if (needSetup) {
-            console.log("Redirect to setup page");
+            log("server", "Redirect to setup page");
             socket.emit("setup");
         }
 
@@ -254,33 +255,40 @@ exports.entryPage = "dashboard";
         // ***************************
 
         socket.on("loginByToken", async (token, callback) => {
+            log("auth", `Login by token. IP=${getClientIp(socket)}`);
 
             try {
                 let decoded = jwt.verify(token, jwtSecret);
 
-                console.log("Username from JWT: " + decoded.username);
+                log("auth", "Username from JWT: " + decoded.username);
 
                 let user = await R.findOne("user", " username = ? AND active = 1 ", [
                     decoded.username,
                 ]);
 
                 if (user) {
-                    debug("afterLogin");
-
+                    log("auth", "afterLogin", "debug");
                     afterLogin(socket, user);
+                    log("auth", "afterLogin ok", "debug");
 
-                    debug("afterLogin ok");
+                    log("auth", `Successfully logged in user ${decoded.username}. IP=${getClientIp(socket)}`);
 
                     callback({
                         ok: true,
                     });
                 } else {
+
+                    log("auth", `Inactive or deleted user ${decoded.username}. IP=${getClientIp(socket)}`);
+
                     callback({
                         ok: false,
                         msg: "The user is inactive or deleted.",
                     });
                 }
             } catch (error) {
+
+                log("auth", `Invalid token for user ${decoded.username}. IP=${getClientIp(socket)}`, "error");
+
                 callback({
                     ok: false,
                     msg: "Invalid token.",
@@ -290,10 +298,11 @@ exports.entryPage = "dashboard";
         });
 
         socket.on("login", async (data, callback) => {
-            console.log("Login");
+            log("auth", `Login by username + password. IP=${getClientIp(socket)}`);
 
             // Login Rate Limit
             if (! await loginRateLimiter.pass(callback)) {
+                log("auth", `Too many failed requests for user ${data.username}. IP=${getClientIp(socket)}`);
                 return;
             }
 
@@ -302,6 +311,9 @@ exports.entryPage = "dashboard";
             if (user) {
                 if (user.twofa_status == 0) {
                     afterLogin(socket, user);
+
+                    log("auth", `Successfully logged in user ${data.username}. IP=${getClientIp(socket)}`);
+
                     callback({
                         ok: true,
                         token: jwt.sign({
@@ -311,6 +323,9 @@ exports.entryPage = "dashboard";
                 }
 
                 if (user.twofa_status == 1 && !data.token) {
+
+                    log("auth", `2FA token required for user ${data.username}. IP=${getClientIp(socket)}`);
+
                     callback({
                         tokenRequired: true,
                     });
@@ -327,6 +342,8 @@ exports.entryPage = "dashboard";
                             socket.userID,
                         ]);
 
+                        log("auth", `Successfully logged in user ${data.username}. IP=${getClientIp(socket)}`);
+
                         callback({
                             ok: true,
                             token: jwt.sign({
@@ -334,6 +351,9 @@ exports.entryPage = "dashboard";
                             }, jwtSecret),
                         });
                     } else {
+
+                        log("auth", `Invalid token provided for user ${data.username}. IP=${getClientIp(socket)}`, "warn");
+
                         callback({
                             ok: false,
                             msg: "Invalid Token!",
@@ -341,6 +361,9 @@ exports.entryPage = "dashboard";
                     }
                 }
             } else {
+
+                log("auth", `Incorrect username or password for user ${data.username}. IP=${getClientIp(socket)}`, "warn");
+
                 callback({
                     ok: false,
                     msg: "Incorrect username or password.",
@@ -405,11 +428,16 @@ exports.entryPage = "dashboard";
                     socket.userID,
                 ]);
 
+                log("auth", `Saved 2FA token for user ${data.username}. IP=${getClientIp(socket)}`);
+
                 callback({
                     ok: true,
                     msg: "2FA Enabled.",
                 });
             } catch (error) {
+
+                log("auth", `Error changing 2FA token for user ${data.username}. IP=${getClientIp(socket)}`, "error");
+
                 callback({
                     ok: false,
                     msg: "Error while trying to change 2FA.",
@@ -425,14 +453,19 @@ exports.entryPage = "dashboard";
                     socket.userID,
                 ]);
 
+                log("auth", `Disabled 2FA token for user ${data.username}. IP=${getClientIp(socket)}`);
+
                 callback({
                     ok: true,
                     msg: "2FA Disabled.",
                 });
             } catch (error) {
+
+                log("auth", `Error disabling 2FA token for user ${data.username}. IP=${getClientIp(socket)}`, "error");
+
                 callback({
                     ok: false,
-                    msg: "Error while trying to change 2FA.",
+                    msg: "Error while trying to disable 2FA.",
                 });
             }
         });
@@ -544,6 +577,8 @@ exports.entryPage = "dashboard";
                 await startMonitor(socket.userID, bean.id);
                 await sendMonitorList(socket);
 
+                log("monitor", `Added Monitor: ${monitorID} User ID: ${socket.userID}`);
+
                 callback({
                     ok: true,
                     msg: "Added Successfully.",
@@ -551,6 +586,9 @@ exports.entryPage = "dashboard";
                 });
 
             } catch (e) {
+
+                log("monitor", `Error adding Monitor: ${monitorID} User ID: ${socket.userID}`, "error");
+
                 callback({
                     ok: false,
                     msg: e.message,
@@ -634,7 +672,7 @@ exports.entryPage = "dashboard";
             try {
                 checkLogin(socket);
 
-                console.log(`Get Monitor: ${monitorID} User ID: ${socket.userID}`);
+                log("monitor", `Get Monitor: ${monitorID} User ID: ${socket.userID}`);
 
                 let bean = await R.findOne("monitor", " id = ? AND user_id = ? ", [
                     monitorID,
@@ -658,7 +696,7 @@ exports.entryPage = "dashboard";
             try {
                 checkLogin(socket);
 
-                console.log(`Get Monitor Beats: ${monitorID} User ID: ${socket.userID}`);
+                log("monitor", `Get Monitor Beats: ${monitorID} User ID: ${socket.userID}`);
 
                 if (period == null) {
                     throw new Error("Invalid period.");
@@ -729,7 +767,7 @@ exports.entryPage = "dashboard";
             try {
                 checkLogin(socket);
 
-                console.log(`Delete Monitor: ${monitorID} User ID: ${socket.userID}`);
+                log("manage", `Delete Monitor: ${monitorID} User ID: ${socket.userID}`);
 
                 if (monitorID in monitorList) {
                     monitorList[monitorID].stop();
@@ -1065,7 +1103,7 @@ exports.entryPage = "dashboard";
 
                 let backupData = JSON.parse(uploadedJSON);
 
-                console.log(`Importing Backup, User ID: ${socket.userID}, Version: ${backupData.version}`);
+                log("manage", `Importing Backup, User ID: ${socket.userID}, Version: ${backupData.version}`);
 
                 let notificationListData = backupData.notificationList;
                 let monitorListData = backupData.monitorList;
@@ -1237,7 +1275,7 @@ exports.entryPage = "dashboard";
             try {
                 checkLogin(socket);
 
-                console.log(`Clear Events Monitor: ${monitorID} User ID: ${socket.userID}`);
+                log("manage", `Clear Events Monitor: ${monitorID} User ID: ${socket.userID}`);
 
                 await R.exec("UPDATE heartbeat SET msg = ?, important = ? WHERE monitor_id = ? ", [
                     "",
@@ -1263,7 +1301,7 @@ exports.entryPage = "dashboard";
             try {
                 checkLogin(socket);
 
-                console.log(`Clear Heartbeats Monitor: ${monitorID} User ID: ${socket.userID}`);
+                log("manage", `Clear Heartbeats Monitor: ${monitorID} User ID: ${socket.userID}`);
 
                 await R.exec("DELETE FROM heartbeat WHERE monitor_id = ?", [
                     monitorID
@@ -1287,7 +1325,7 @@ exports.entryPage = "dashboard";
             try {
                 checkLogin(socket);
 
-                console.log(`Clear Statistics User ID: ${socket.userID}`);
+                log("manage", `Clear Statistics User ID: ${socket.userID}`);
 
                 await R.exec("DELETE FROM heartbeat");
 
@@ -1307,24 +1345,24 @@ exports.entryPage = "dashboard";
         statusPageSocketHandler(socket);
         databaseSocketHandler(socket);
 
-        debug("added all socket handlers");
+        log("server", "added all socket handlers", "debug");
 
         // ***************************
         // Better do anything after added all socket handlers here
         // ***************************
 
-        debug("check auto login");
+        log("auth", "check auto login", "debug");
         if (await setting("disableAuth")) {
-            console.log("Disabled Auth: auto login to admin");
+            log("auth", "Disabled Auth: auto login to admin");
             afterLogin(socket, await R.findOne("user"));
             socket.emit("autoLogin");
         } else {
-            debug("need auth");
+            log("auth", "need auth", "debug");
         }
 
     });
 
-    console.log("Init the server");
+    log("server", "Init the server");
 
     server.once("error", async (err) => {
         console.error("Cannot listen: " + err.message);
@@ -1333,9 +1371,9 @@ exports.entryPage = "dashboard";
 
     server.listen(port, hostname, () => {
         if (hostname) {
-            console.log(`Listening on ${hostname}:${port}`);
+            log("server", `Listening on ${hostname}:${port}`);
         } else {
-            console.log(`Listening on ${port}`);
+            log("server", `Listening on ${port}`);
         }
         startMonitors();
         checkVersion.startInterval();
@@ -1419,13 +1457,13 @@ async function getMonitorJSONList(userID) {
 
 async function initDatabase() {
     if (! fs.existsSync(Database.path)) {
-        console.log("Copying Database");
+        log("server", "Copying Database");
         fs.copyFileSync(Database.templatePath, Database.path);
     }
 
-    console.log("Connecting to the Database");
+    log("server", "Connecting to the Database");
     await Database.connect();
-    console.log("Connected");
+    log("server", "Connected");
 
     // Patch the database
     await Database.patch();
@@ -1435,16 +1473,16 @@ async function initDatabase() {
     ]);
 
     if (! jwtSecretBean) {
-        console.log("JWT secret is not found, generate one.");
+        log("server", "JWT secret is not found, generate one.");
         jwtSecretBean = await initJWTSecret();
-        console.log("Stored JWT secret into database");
+        log("server", "Stored JWT secret into database");
     } else {
-        console.log("Load JWT secret from database.");
+        log("server", "Load JWT secret from database.");
     }
 
     // If there is no record in user table, it is a new Uptime Kuma instance, need to setup
     if ((await R.count("user")) === 0) {
-        console.log("No user, need setup");
+        log("server", "No user, need setup");
         needSetup = true;
     }
 
@@ -1454,7 +1492,7 @@ async function initDatabase() {
 async function startMonitor(userID, monitorID) {
     await checkOwner(userID, monitorID);
 
-    console.log(`Resume Monitor: ${monitorID} User ID: ${userID}`);
+    log("manage", `Resume Monitor: ${monitorID} User ID: ${userID}`);
 
     await R.exec("UPDATE monitor SET active = 1 WHERE id = ? AND user_id = ? ", [
         monitorID,
@@ -1480,7 +1518,7 @@ async function restartMonitor(userID, monitorID) {
 async function pauseMonitor(userID, monitorID) {
     await checkOwner(userID, monitorID);
 
-    console.log(`Pause Monitor: ${monitorID} User ID: ${userID}`);
+    log("manage", `Pause Monitor: ${monitorID} User ID: ${userID}`);
 
     await R.exec("UPDATE monitor SET active = 0 WHERE id = ? AND user_id = ? ", [
         monitorID,
@@ -1510,10 +1548,10 @@ async function startMonitors() {
 }
 
 async function shutdownFunction(signal) {
-    console.log("Shutdown requested");
-    console.log("Called signal: " + signal);
+    log("server", "Shutdown requested");
+    log("server", "Called signal: " + signal);
 
-    console.log("Stopping all monitors");
+    log("server", "Stopping all monitors");
     for (let id in monitorList) {
         let monitor = monitorList[id];
         monitor.stop();
@@ -1522,8 +1560,12 @@ async function shutdownFunction(signal) {
     await Database.close();
 }
 
+function getClientIp(socket) {
+    return socket.client.conn.remoteAddress.replace(/^.*:/, "")
+}
+
 function finalFunction() {
-    console.log("Graceful shutdown successful!");
+    log("server", "Graceful shutdown successful!");
 }
 
 gracefulShutdown(server, {
diff --git a/server/socket-handlers/status-page-socket-handler.js b/server/socket-handlers/status-page-socket-handler.js
index 5826277c7..a05b311d3 100644
--- a/server/socket-handlers/status-page-socket-handler.js
+++ b/server/socket-handlers/status-page-socket-handler.js
@@ -1,7 +1,7 @@
 const { R } = require("redbean-node");
 const { checkLogin, setSettings } = require("../util-server");
 const dayjs = require("dayjs");
-const { debug } = require("../../src/util");
+const { log } = require("../../src/util");
 const ImageDataURI = require("../image-data-uri");
 const Database = require("../database");
 const apicache = require("../modules/apicache");
@@ -138,8 +138,8 @@ module.exports.statusPageSocketHandler = (socket) => {
                 group.id = groupBean.id;
             }
 
-            // Delete groups that not in the list
-            debug("Delete groups that not in the list");
+            // Delete groups that are not in the list
+            log("socket", "Delete groups that are not in the list", "debug");
             const slots = groupIDList.map(() => "?").join(",");
             await R.exec(`DELETE FROM \`group\` WHERE id NOT IN (${slots})`, groupIDList);
 
diff --git a/server/util-server.js b/server/util-server.js
index 68f59f67f..6b1fc522e 100644
--- a/server/util-server.js
+++ b/server/util-server.js
@@ -1,7 +1,7 @@
 const tcpp = require("tcp-ping");
 const Ping = require("./ping-lite");
 const { R } = require("redbean-node");
-const { debug } = require("../src/util");
+const { log } = require("../src/util");
 const passwordHash = require("./password-hash");
 const dayjs = require("dayjs");
 const { Resolver } = require("dns");
@@ -119,7 +119,7 @@ exports.setting = async function (key) {
 
     try {
         const v = JSON.parse(value);
-        debug(`Get Setting: ${key}: ${v}`);
+        log("util", `Get Setting: ${key}: ${v}`, "debug");
         return v;
     } catch (e) {
         return value;
@@ -206,7 +206,7 @@ const parseCertificateInfo = function (info) {
     const existingList = {};
 
     while (link) {
-        debug(`[${i}] ${link.fingerprint}`);
+        log("util", `[${i}] ${link.fingerprint}`, "debug");
 
         if (!link.valid_from || !link.valid_to) {
             break;
@@ -221,7 +221,7 @@ const parseCertificateInfo = function (info) {
         if (link.issuerCertificate == null) {
             break;
         } else if (link.issuerCertificate.fingerprint in existingList) {
-            debug(`[Last] ${link.issuerCertificate.fingerprint}`);
+            log("util", `[Last] ${link.issuerCertificate.fingerprint}`, "debug");
             link.issuerCertificate = null;
             break;
         } else {
@@ -242,7 +242,7 @@ exports.checkCertificate = function (res) {
     const info = res.request.res.socket.getPeerCertificate(true);
     const valid = res.request.res.socket.authorized || false;
 
-    debug("Parsing Certificate Info");
+    log("util", "Parsing Certificate Info", "debug");
     const parsedInfo = parseCertificateInfo(info);
 
     return {
@@ -345,7 +345,7 @@ exports.startUnitTest = async () => {
  */
 exports.convertToUTF8 = (body) => {
     const guessEncoding = chardet.detect(body);
-    //debug("Guess Encoding: " + guessEncoding);
+    //log("util", "Guess Encoding: " + guessEncoding, "debug");
     const str = iconv.decode(body, guessEncoding);
     return str.toString();
 };
diff --git a/src/util.js b/src/util.js
index b2df7ac79..1b8020df7 100644
--- a/src/util.js
+++ b/src/util.js
@@ -6,10 +6,10 @@
 //
 // Backend uses the compiled file util.js
 // Frontend uses util.ts
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.getMonitorRelativeURL = exports.genSecret = exports.getCryptoRandomInt = exports.getRandomInt = exports.getRandomArbitrary = exports.TimeLogger = exports.polyfill = exports.debug = exports.ucfirst = exports.sleep = exports.flipStatus = exports.STATUS_PAGE_PARTIAL_DOWN = exports.STATUS_PAGE_ALL_UP = exports.STATUS_PAGE_ALL_DOWN = exports.PENDING = exports.UP = exports.DOWN = exports.appName = exports.isDev = void 0;
-const _dayjs = require("dayjs");
-const dayjs = _dayjs;
+exports.__esModule = true;
+exports.getMonitorRelativeURL = exports.genSecret = exports.getCryptoRandomInt = exports.getRandomInt = exports.getRandomArbitrary = exports.TimeLogger = exports.polyfill = exports.log = exports.ucfirst = exports.sleep = exports.flipStatus = exports.STATUS_PAGE_PARTIAL_DOWN = exports.STATUS_PAGE_ALL_UP = exports.STATUS_PAGE_ALL_DOWN = exports.PENDING = exports.UP = exports.DOWN = exports.appName = exports.isDev = void 0;
+var _dayjs = require("dayjs");
+var dayjs = _dayjs;
 exports.isDev = process.env.NODE_ENV === "development";
 exports.appName = "Uptime Kuma";
 exports.DOWN = 0;
@@ -29,7 +29,7 @@ function flipStatus(s) {
 }
 exports.flipStatus = flipStatus;
 function sleep(ms) {
-    return new Promise(resolve => setTimeout(resolve, ms));
+    return new Promise(function (resolve) { return setTimeout(resolve, ms); });
 }
 exports.sleep = sleep;
 /**
@@ -40,16 +40,36 @@ function ucfirst(str) {
     if (!str) {
         return str;
     }
-    const firstLetter = str.substr(0, 1);
+    var firstLetter = str.substr(0, 1);
     return firstLetter.toUpperCase() + str.substr(1);
 }
 exports.ucfirst = ucfirst;
-function debug(msg) {
-    if (exports.isDev) {
-        console.log(msg);
+// log levels = info / warn / error / debug
+function log(module, msg, level) {
+    if (level === void 0) { level = "info"; }
+    module = module.toUpperCase();
+    level = level.toUpperCase();
+    var now = new Date().toISOString();
+    var formattedMessage = (typeof msg === "string") ? now + " [" + module + "] " + level + ": " + msg : msg;
+    if (level === "INFO") {
+        console.log(formattedMessage);
+    }
+    else if (level === "WARN") {
+        console.warn(formattedMessage);
+    }
+    else if (level === "ERROR") {
+        console.error(formattedMessage);
+    }
+    else if (level === "DEBUG") {
+        if (exports.isDev) {
+            console.debug(formattedMessage);
+        }
+    }
+    else {
+        console.log(formattedMessage);
     }
 }
-exports.debug = debug;
+exports.log = log;
 function polyfill() {
     /**
      * String.prototype.replaceAll() polyfill
@@ -69,16 +89,17 @@ function polyfill() {
     }
 }
 exports.polyfill = polyfill;
-class TimeLogger {
-    constructor() {
+var TimeLogger = /** @class */ (function () {
+    function TimeLogger() {
         this.startTime = dayjs().valueOf();
     }
-    print(name) {
+    TimeLogger.prototype.print = function (name) {
         if (exports.isDev && process.env.TIMELOGGER === "1") {
             console.log(name + ": " + (dayjs().valueOf() - this.startTime) + "ms");
         }
-    }
-}
+    };
+    return TimeLogger;
+}());
 exports.TimeLogger = TimeLogger;
 /**
  * Returns a random number between min (inclusive) and max (exclusive)
@@ -106,12 +127,12 @@ exports.getRandomInt = getRandomInt;
  * Returns either the NodeJS crypto.randomBytes() function or its
  * browser equivalent implemented via window.crypto.getRandomValues()
  */
-let getRandomBytes = ((typeof window !== 'undefined' && window.crypto)
+var getRandomBytes = ((typeof window !== 'undefined' && window.crypto)
     // Browsers
     ? function () {
-        return (numBytes) => {
-            let randomBytes = new Uint8Array(numBytes);
-            for (let i = 0; i < numBytes; i += 65536) {
+        return function (numBytes) {
+            var randomBytes = new Uint8Array(numBytes);
+            for (var i = 0; i < numBytes; i += 65536) {
                 window.crypto.getRandomValues(randomBytes.subarray(i, i + Math.min(numBytes - i, 65536)));
             }
             return randomBytes;
@@ -123,13 +144,13 @@ let getRandomBytes = ((typeof window !== 'undefined' && window.crypto)
     })();
 function getCryptoRandomInt(min, max) {
     // synchronous version of: https://github.com/joepie91/node-random-number-csprng
-    const range = max - min;
+    var range = max - min;
     if (range >= Math.pow(2, 32))
         console.log("Warning! Range is too large.");
-    let tmpRange = range;
-    let bitsNeeded = 0;
-    let bytesNeeded = 0;
-    let mask = 1;
+    var tmpRange = range;
+    var bitsNeeded = 0;
+    var bytesNeeded = 0;
+    var mask = 1;
     while (tmpRange > 0) {
         if (bitsNeeded % 8 === 0)
             bytesNeeded += 1;
@@ -137,9 +158,9 @@ function getCryptoRandomInt(min, max) {
         mask = mask << 1 | 1;
         tmpRange = tmpRange >>> 1;
     }
-    const randomBytes = getRandomBytes(bytesNeeded);
-    let randomValue = 0;
-    for (let i = 0; i < bytesNeeded; i++) {
+    var randomBytes = getRandomBytes(bytesNeeded);
+    var randomValue = 0;
+    for (var i = 0; i < bytesNeeded; i++) {
         randomValue |= randomBytes[i] << 8 * i;
     }
     randomValue = randomValue & mask;
@@ -151,11 +172,12 @@ function getCryptoRandomInt(min, max) {
     }
 }
 exports.getCryptoRandomInt = getCryptoRandomInt;
-function genSecret(length = 64) {
-    let secret = "";
-    const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
-    const charsLength = chars.length;
-    for (let i = 0; i < length; i++) {
+function genSecret(length) {
+    if (length === void 0) { length = 64; }
+    var secret = "";
+    var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+    var charsLength = chars.length;
+    for (var i = 0; i < length; i++) {
         secret += chars.charAt(getCryptoRandomInt(0, charsLength - 1));
     }
     return secret;
diff --git a/src/util.ts b/src/util.ts
index 633d933ea..6fde8f3f3 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -49,9 +49,26 @@ export function ucfirst(str: string) {
     return firstLetter.toUpperCase() + str.substr(1);
 }
 
-export function debug(msg: any) {
-    if (isDev) {
-        console.log(msg);
+// log levels = info / warn / error / debug
+export function log(module: string, msg: any, level:string = "info") {
+    module = module.toUpperCase();
+    level = level.toUpperCase();
+
+    const now = new Date().toISOString();
+    const formattedMessage = (typeof msg === "string") ? `${now} [${module}] ${level}: ${msg}` : msg;
+
+    if (level === "INFO") {
+        console.log(formattedMessage);
+    } else if (level === "WARN") {
+        console.warn(formattedMessage);
+    } else if (level === "ERROR") {
+        console.error(formattedMessage);
+    } else if (level === "DEBUG") {
+        if (isDev) {
+            console.debug(formattedMessage);
+        }
+    } else {
+        console.log(formattedMessage);
     }
 }