diff --git a/app/vmagent/main.go b/app/vmagent/main.go
index 1f2e28249e..04c6cd8b26 100644
--- a/app/vmagent/main.go
+++ b/app/vmagent/main.go
@@ -228,7 +228,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request) bool {
 			errMsg := fmt.Sprintf("waiting for scrapes to init, left: %d", rdy)
 			http.Error(w, errMsg, http.StatusTooEarly)
 		} else {
-			w.Header().Set("Content-Type", "text/plain")
+			w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 			w.WriteHeader(http.StatusOK)
 			w.Write([]byte("OK"))
 		}
diff --git a/app/vmalert/datasource/vm.go b/app/vmalert/datasource/vm.go
index bf57a04be7..7e0bc4ce4b 100644
--- a/app/vmalert/datasource/vm.go
+++ b/app/vmalert/datasource/vm.go
@@ -82,7 +82,7 @@ func (s *VMStorage) Query(ctx context.Context, query string) ([]Metric, error) {
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Content-Type", "application/json; charset=utf-8")
 	if s.basicAuthPass != "" {
 		req.SetBasicAuth(s.basicAuthUser, s.basicAuthPass)
 	}
diff --git a/app/vmalert/notifier/alertmanager.go b/app/vmalert/notifier/alertmanager.go
index f7dd036151..a24f5f723a 100644
--- a/app/vmalert/notifier/alertmanager.go
+++ b/app/vmalert/notifier/alertmanager.go
@@ -28,7 +28,7 @@ func (am *AlertManager) Send(ctx context.Context, alerts []Alert) error {
 	if err != nil {
 		return err
 	}
-	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Content-Type", "application/json; charset=utf-8")
 	req = req.WithContext(ctx)
 	if am.basicAuthPass != "" {
 		req.SetBasicAuth(am.basicAuthUser, am.basicAuthPass)
diff --git a/app/vmalert/web.go b/app/vmalert/web.go
index dbd90fa9aa..a095356d97 100644
--- a/app/vmalert/web.go
+++ b/app/vmalert/web.go
@@ -40,7 +40,7 @@ func (rh *requestHandler) handler(w http.ResponseWriter, r *http.Request) bool {
 			httpserver.Errorf(w, r, "error in %q: %s", r.URL.Path, err)
 			return true
 		}
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		w.Write(data)
 		return true
 	case "/api/v1/alerts":
@@ -49,7 +49,7 @@ func (rh *requestHandler) handler(w http.ResponseWriter, r *http.Request) bool {
 			httpserver.Errorf(w, r, "error in %q: %s", r.URL.Path, err)
 			return true
 		}
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		w.Write(data)
 		return true
 	case "/-/reload":
@@ -67,7 +67,7 @@ func (rh *requestHandler) handler(w http.ResponseWriter, r *http.Request) bool {
 			httpserver.Errorf(w, r, "error in %q: %s", r.URL.Path, err)
 			return true
 		}
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		w.Write(data)
 		return true
 	}
diff --git a/app/vmselect/graphite/graphite.go b/app/vmselect/graphite/graphite.go
index e28012703c..fe683a0d66 100644
--- a/app/vmselect/graphite/graphite.go
+++ b/app/vmselect/graphite/graphite.go
@@ -88,9 +88,9 @@ func MetricsFindHandler(startTime time.Time, at *auth.Token, w http.ResponseWrit
 	}
 	paths = deduplicatePaths(paths, delimiter)
 	sortPaths(paths, delimiter)
-	contentType := "application/json"
+	contentType := "application/json; charset=utf-8"
 	if jsonp != "" {
-		contentType = "text/javascript"
+		contentType = "text/javascript; charset=utf-8"
 	}
 	w.Header().Set("Content-Type", contentType)
 	bw := bufferedwriter.Get(w)
@@ -173,9 +173,9 @@ func MetricsExpandHandler(startTime time.Time, at *auth.Token, w http.ResponseWr
 		}
 		m[query] = paths
 	}
-	contentType := "application/json"
+	contentType := "application/json; charset=utf-8"
 	if jsonp != "" {
-		contentType = "text/javascript"
+		contentType = "text/javascript; charset=utf-8"
 	}
 	w.Header().Set("Content-Type", contentType)
 	if groupByExpr {
@@ -225,9 +225,9 @@ func MetricsIndexHandler(startTime time.Time, at *auth.Token, w http.ResponseWri
 	if isPartial && searchutils.GetDenyPartialResponse(r) {
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
-	contentType := "application/json"
+	contentType := "application/json; charset=utf-8"
 	if jsonp != "" {
-		contentType = "text/javascript"
+		contentType = "text/javascript; charset=utf-8"
 	}
 	w.Header().Set("Content-Type", contentType)
 	bw := bufferedwriter.Get(w)
diff --git a/app/vmselect/main.go b/app/vmselect/main.go
index d01e2f555e..c2a41ac9c6 100644
--- a/app/vmselect/main.go
+++ b/app/vmselect/main.go
@@ -339,19 +339,19 @@ func selectHandler(startTime time.Time, w http.ResponseWriter, r *http.Request,
 	case "prometheus/api/v1/rules":
 		// Return dumb placeholder
 		rulesRequests.Inc()
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		fmt.Fprintf(w, "%s", `{"status":"success","data":{"groups":[]}}`)
 		return true
 	case "prometheus/api/v1/alerts":
 		// Return dumb placehloder
 		alertsRequests.Inc()
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		fmt.Fprintf(w, "%s", `{"status":"success","data":{"alerts":[]}}`)
 		return true
 	case "prometheus/api/v1/metadata":
 		// Return dumb placeholder
 		metadataRequests.Inc()
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		fmt.Fprintf(w, "%s", `{"status":"success","data":{}}`)
 		return true
 	default:
@@ -378,7 +378,7 @@ func deleteHandler(startTime time.Time, w http.ResponseWriter, r *http.Request,
 func sendPrometheusError(w http.ResponseWriter, r *http.Request, err error) {
 	logger.Warnf("error in %q: %s", r.RequestURI, err)
 
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	statusCode := http.StatusUnprocessableEntity
 	var esc *httpserver.ErrorWithStatusCode
 	if errors.As(err, &esc) {
diff --git a/app/vmselect/prometheus/prometheus.go b/app/vmselect/prometheus/prometheus.go
index 663ae67429..c4edb8f0e5 100644
--- a/app/vmselect/prometheus/prometheus.go
+++ b/app/vmselect/prometheus/prometheus.go
@@ -96,7 +96,7 @@ func FederateHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter,
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
 
-	w.Header().Set("Content-Type", "text/plain")
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	err = rss.RunParallel(func(rs *netstorage.Result, workerID uint) error {
@@ -161,7 +161,7 @@ func ExportCSVHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter
 		MaxTimestamp: end,
 		TagFilterss:  tagFilterss,
 	}
-	w.Header().Set("Content-Type", "text/csv")
+	w.Header().Set("Content-Type", "text/csv; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 
@@ -350,9 +350,9 @@ func exportHandler(at *auth.Token, w http.ResponseWriter, r *http.Request, match
 		WriteExportJSONLine(bb, xb)
 		resultsCh <- bb
 	}
-	contentType := "application/stream+json"
+	contentType := "application/stream+json; charset=utf-8"
 	if format == "prometheus" {
-		contentType = "text/plain"
+		contentType = "text/plain; charset=utf-8"
 		writeLineFunc = func(xb *exportBlock, resultsCh chan<- *quicktemplate.ByteBuffer) {
 			bb := quicktemplate.AcquireByteBuffer()
 			WriteExportPrometheusLine(bb, xb)
@@ -631,7 +631,7 @@ func LabelValuesHandler(startTime time.Time, at *auth.Token, labelName string, w
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
 
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteLabelValuesResponse(bw, labelValues)
@@ -714,7 +714,7 @@ func LabelsCountHandler(startTime time.Time, at *auth.Token, w http.ResponseWrit
 	if isPartial && searchutils.GetDenyPartialResponse(r) {
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteLabelsCountResponse(bw, labelEntries)
@@ -768,7 +768,7 @@ func TSDBStatusHandler(startTime time.Time, at *auth.Token, w http.ResponseWrite
 	if isPartial && searchutils.GetDenyPartialResponse(r) {
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteTSDBStatusResponse(bw, status)
@@ -842,7 +842,7 @@ func LabelsHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
 
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteLabelsResponse(bw, labels)
@@ -913,8 +913,7 @@ func SeriesCountHandler(startTime time.Time, at *auth.Token, w http.ResponseWrit
 	if isPartial && searchutils.GetDenyPartialResponse(r) {
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
-
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteSeriesCountResponse(bw, n)
@@ -977,7 +976,7 @@ func SeriesHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r
 		return fmt.Errorf("cannot return full response, since some of vmstorage nodes are unavailable")
 	}
 
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	resultsCh := make(chan *quicktemplate.ByteBuffer)
@@ -1117,7 +1116,7 @@ func QueryHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r
 		}
 	}
 
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteQueryResponse(bw, result)
@@ -1219,7 +1218,7 @@ func queryRangeHandler(startTime time.Time, at *auth.Token, w http.ResponseWrite
 	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/153
 	result = removeEmptyValuesAndTimeseries(result)
 
-	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	bw := bufferedwriter.Get(w)
 	defer bufferedwriter.Put(bw)
 	WriteQueryRangeResponse(bw, result)
diff --git a/app/vmstorage/main.go b/app/vmstorage/main.go
index 7888d99bb4..a482740095 100644
--- a/app/vmstorage/main.go
+++ b/app/vmstorage/main.go
@@ -169,7 +169,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request, strg *storage.Storag
 
 	switch path {
 	case "/create":
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		snapshotPath, err := strg.CreateSnapshot()
 		if err != nil {
 			err = fmt.Errorf("cannot create snapshot: %w", err)
@@ -179,7 +179,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request, strg *storage.Storag
 		fmt.Fprintf(w, `{"status":"ok","snapshot":%q}`, snapshotPath)
 		return true
 	case "/list":
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		snapshots, err := strg.ListSnapshots()
 		if err != nil {
 			err = fmt.Errorf("cannot list snapshots: %w", err)
@@ -196,7 +196,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request, strg *storage.Storag
 		fmt.Fprintf(w, `]}`)
 		return true
 	case "/delete":
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		snapshotName := r.FormValue("snapshot")
 		if err := strg.DeleteSnapshot(snapshotName); err != nil {
 			err = fmt.Errorf("cannot delete snapshot %q: %w", snapshotName, err)
@@ -206,7 +206,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request, strg *storage.Storag
 		fmt.Fprintf(w, `{"status":"ok"}`)
 		return true
 	case "/delete_all":
-		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		snapshots, err := strg.ListSnapshots()
 		if err != nil {
 			err = fmt.Errorf("cannot list snapshots: %w", err)
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 759deea641..e93b9661a6 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -10,6 +10,8 @@
 * FEATURE: add `-search.treatDotsAsIsInRegexps` command-line flag, which can be used for automatic escaping of dots in regexp label filters used in queries.
   For example, if `-search.treatDotsAsIsInRegexps` is set, then the query `foo{bar=~"aaa.bb.cc|dd.eee"}` is automatically converted to `foo{bar=~"aaa\\.bb\\.cc|dd\\.eee"}`.
   This may be useful for querying Graphite data.
+* FEATURE: consistently return text-based HTTP responses such as `plain/text` and `application/json` with `charset=utf-8`.
+  See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/897
 
 * BUGFIX: do not return data points in the end of the selected time range for time series ending in the middle of the selected time range.
   See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/887 and https://github.com/VictoriaMetrics/VictoriaMetrics/issues/845
diff --git a/lib/httpserver/httpserver.go b/lib/httpserver/httpserver.go
index 6a0efbbefb..0563f24e56 100644
--- a/lib/httpserver/httpserver.go
+++ b/lib/httpserver/httpserver.go
@@ -204,7 +204,7 @@ func handlerWrapper(s *server, w http.ResponseWriter, r *http.Request, rh Reques
 	r.URL.Path = path
 	switch r.URL.Path {
 	case "/health":
-		w.Header().Set("Content-Type", "text/plain")
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 		deadline := atomic.LoadInt64(&s.shutdownDelayDeadline)
 		if deadline <= 0 {
 			w.Write([]byte("OK"))
@@ -236,7 +236,7 @@ func handlerWrapper(s *server, w http.ResponseWriter, r *http.Request, rh Reques
 	case "/metrics":
 		metricsRequests.Inc()
 		startTime := time.Now()
-		w.Header().Set("Content-Type", "text/plain")
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 		WritePrometheusMetrics(w)
 		metricsHandlerDuration.UpdateDuration(startTime)
 		return
@@ -365,7 +365,7 @@ func (zrw *gzipResponseWriter) Write(p []byte) (int, error) {
 			if h.Get("Content-Type") == "" {
 				// Disable auto-detection of content-type, since it
 				// is incorrectly detected after the compression.
-				h.Set("Content-Type", "text/html")
+				h.Set("Content-Type", "text/html; charset=utf-8")
 			}
 		}
 		zrw.writeHeader()