diff --git a/promql/value.go b/promql/value.go
index cd36c9a7e..861dba6ae 100644
--- a/promql/value.go
+++ b/promql/value.go
@@ -146,6 +146,9 @@ func (p Point) MarshalJSON() ([]byte, error) {
 	it := p.H.AllBucketIterator()
 	for it.Next() {
 		bucket := it.At()
+		if bucket.Count == 0 {
+			continue // No need to expose empty buckets in JSON.
+		}
 		boundaries := 2 // Exclusive on both sides AKA open interval.
 		if bucket.LowerInclusive {
 			if bucket.UpperInclusive {
diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index 92dc254c3..ca63927a4 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -513,188 +513,6 @@ func (api *API) queryRange(r *http.Request) (result apiFuncResult) {
 	}, nil, res.Warnings, qry.Close}
 }
 
-// TODO: remove this when we have sparse histogram support in PromQL.
-// This is a hack to query sparse histogram for buckets.
-//func (api *API) queryRange(r *http.Request) (result apiFuncResult) {
-//	start, err := parseTime(r.FormValue("start"))
-//	if err != nil {
-//		return invalidParamError(err, "start")
-//	}
-//	end, err := parseTime(r.FormValue("end"))
-//	if err != nil {
-//		return invalidParamError(err, "end")
-//	}
-//	if end.Before(start) {
-//		return invalidParamError(errors.New("end timestamp must not be before start time"), "end")
-//	}
-//
-//	step, err := parseDuration(r.FormValue("step"))
-//	if err != nil {
-//		return invalidParamError(err, "step")
-//	}
-//
-//	if step <= 0 {
-//		return invalidParamError(errors.New("zero or negative query resolution step widths are not accepted. Try a positive integer"), "step")
-//	}
-//
-//	// For safety, limit the number of returned points per timeseries.
-//	// This is sufficient for 60s resolution for a week or 1h resolution for a year.
-//	if end.Sub(start)/step > 11000 {
-//		err := errors.New("exceeded maximum resolution of 11,000 points per timeseries. Try decreasing the query resolution (?step=XX)")
-//		return apiFuncResult{nil, &apiError{errorBadData, err}, nil, nil}
-//	}
-//
-//	ctx := r.Context()
-//	if to := r.FormValue("timeout"); to != "" {
-//		var cancel context.CancelFunc
-//		timeout, err := parseDuration(to)
-//		if err != nil {
-//			return invalidParamError(err, "timeout")
-//		}
-//
-//		ctx, cancel = context.WithTimeout(ctx, timeout)
-//		defer cancel()
-//	}
-//
-//	expr, err := parser.ParseExpr(r.FormValue("query"))
-//	if err != nil {
-//		return apiFuncResult{nil, &apiError{errorBadData, err}, nil, nil}
-//	}
-//
-//	selectors := parser.ExtractSelectors(expr)
-//	if len(selectors) < 1 {
-//		return apiFuncResult{nil, nil, nil, nil}
-//	}
-//
-//	if len(selectors) > 1 {
-//		return apiFuncResult{nil, &apiError{errorBadData, errors.New("need exactly 1 selector")}, nil, nil}
-//	}
-//
-//	hasRate, rateDuration := false, time.Duration(0)
-//	parser.Inspect(expr, func(node parser.Node, path []parser.Node) error {
-//		switch n := node.(type) {
-//		case *parser.Call:
-//			if n.Func.Name == "rate" {
-//				hasRate = true
-//				rateDuration = n.Args[0].(*parser.MatrixSelector).Range
-//				return errors.New("stop it here")
-//			}
-//		}
-//		return nil
-//	})
-//	var numRateSamples int
-//	if hasRate {
-//		numRateSamples = int(end.Sub(start)/step + 1)
-//		if start.Add(time.Duration(numRateSamples-1) * step).After(end) {
-//			numRateSamples--
-//		}
-//		start = start.Add(-rateDuration) // Adjusting for the first point lookback.
-//	}
-//
-//	q, err := api.Queryable.Querier(ctx, timestamp.FromTime(start), timestamp.FromTime(end))
-//	if err != nil {
-//		return apiFuncResult{nil, &apiError{errorExec, err}, nil, nil}
-//	}
-//
-//	res := promql.Matrix{}
-//	ss := q.Select(true, nil, selectors[0]...)
-//
-//	for ss.Next() {
-//		resSeries := make(map[float64]promql.Series) // le -> series.
-//
-//		s := ss.At()
-//		it := s.Iterator()
-//		for it.Next() { // Per histogram.
-//			t, h := it.AtHistogram()
-//			buckets := histogram.CumulativeExpandSparseHistogram(h)
-//			for buckets.Next() {
-//				// Every bucket is a different series with different "le".
-//				b := buckets.At()
-//				rs, ok := resSeries[b.Le]
-//				if !ok {
-//					rs = promql.Series{
-//						Metric: append(
-//							s.Labels(),
-//							labels.Label{Name: "le", Value: fmt.Sprintf("%.16f", b.Le)}, // TODO: Set some precision for 'le'?
-//						),
-//					}
-//					sort.Sort(rs.Metric)
-//					resSeries[b.Le] = rs
-//				}
-//
-//				rs.Points = append(rs.Points, promql.Point{
-//					T: t,
-//					V: float64(b.Count),
-//				})
-//				resSeries[b.Le] = rs
-//			}
-//			if buckets.Err() != nil {
-//				return apiFuncResult{nil, &apiError{errorExec, buckets.Err()}, nil, nil}
-//			}
-//		}
-//
-//		for _, rs := range resSeries {
-//			res = append(res, rs)
-//		}
-//	}
-//
-//	if hasRate {
-//		newRes := make(promql.Matrix, len(res))
-//		for i := range newRes {
-//			newRes[i].Metric = res[i].Metric
-//			points := make([]promql.Point, numRateSamples)
-//
-//			rawPoints := res[i].Points
-//
-//			startIdx, endIdx := 0, 0
-//			for idx := range points {
-//				pointTime := start.Add(time.Duration(idx) * step)
-//				lookbackTime := pointTime.Add(-rateDuration)
-//				points[idx].T = timestamp.FromTime(pointTime)
-//				if len(rawPoints) == 0 {
-//					continue
-//				}
-//
-//				for startIdx < len(rawPoints) && timestamp.Time(rawPoints[startIdx].T).Before(lookbackTime) {
-//					startIdx++
-//				}
-//				if startIdx >= len(rawPoints) {
-//					startIdx = len(rawPoints) - 1
-//				}
-//
-//				for endIdx < len(rawPoints) && timestamp.Time(rawPoints[endIdx].T).Before(pointTime) {
-//					endIdx++
-//				}
-//				if endIdx >= len(rawPoints) {
-//					endIdx = len(rawPoints) - 1
-//				} else if timestamp.Time(rawPoints[endIdx].T).After(pointTime) && (len(rawPoints) == 1 || endIdx == 0) {
-//					continue
-//				} else {
-//					endIdx--
-//				}
-//
-//				valDiff := rawPoints[endIdx].V - rawPoints[startIdx].V
-//				timeDiffSeconds := float64(timestamp.Time(rawPoints[endIdx].T).Sub(timestamp.Time(rawPoints[startIdx].T))) / float64(time.Second)
-//
-//				if timeDiffSeconds != 0 {
-//					points[idx].V = valDiff / timeDiffSeconds
-//				}
-//			}
-//
-//			newRes[i].Points = points
-//		}
-//
-//		res = newRes
-//	}
-//
-//	sort.Sort(res)
-//
-//	return apiFuncResult{&queryData{
-//		ResultType: res.Type(),
-//		Result:     res,
-//	}, nil, nil, nil}
-//}
-
 func (api *API) queryExemplars(r *http.Request) apiFuncResult {
 	start, err := parseTimeParam(r, "start", minTime)
 	if err != nil {
@@ -1984,13 +1802,16 @@ func marshalHistogram(h *histogram.FloatHistogram, stream *jsoniter.Stream) {
 	bucketFound := false
 	it := h.AllBucketIterator()
 	for it.Next() {
+		bucket := it.At()
+		if bucket.Count == 0 {
+			continue // No need to expose empty buckets in JSON.
+		}
 		stream.WriteMore()
 		if !bucketFound {
 			stream.WriteObjectField(`buckets`)
 			stream.WriteArrayStart()
 		}
 		bucketFound = true
-		bucket := it.At()
 		boundaries := 2 // Exclusive on both sides AKA open interval.
 		if bucket.LowerInclusive {
 			if bucket.UpperInclusive {