diff --git a/CHANGELOG.md b/CHANGELOG.md
index a7953363fe3e0ee93ee0a07445e47abe135f3a44..f72fa27c6d476e7c0f98893e505125beffdaa251 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ The format is based on [keep a changelog](http://keepachangelog.com) and this pr
 ## [Unreleased]
 ### Added
 - Add ctx field to access http request headers in the runtimes.
+- New JS runtime stringToBinary and binaryToString functions.
 
 ### Fixed
 - Gracefully close Lua matches when call queue fills up.
@@ -15,6 +16,7 @@ The format is based on [keep a changelog](http://keepachangelog.com) and this pr
 
 ### Changed
 - Set JS runtime custom error message as the returned payload message in RPC requests.
+- JS runtime match data changed to Uint8Array.
 
 ## [3.9.0] - 2021-10-29
 ### Added
diff --git a/server/runtime_javascript_match_core.go b/server/runtime_javascript_match_core.go
index e5c72661a6a2726eefdf95e419f834944ca9b350..7c03998706d55942c415949d7614b0eaef434bbb 100644
--- a/server/runtime_javascript_match_core.go
+++ b/server/runtime_javascript_match_core.go
@@ -393,10 +393,10 @@ func (rm *RuntimeJavaScriptMatchCore) MatchLoop(tick int64, state interface{}, i
 		msgMap := make(map[string]interface{}, 5)
 		msgMap["sender"] = presenceMap
 		msgMap["opCode"] = msg.OpCode
-		if msg.Data != nil {
-			msgMap["data"] = string(msg.Data)
-		} else {
+		if msg.Data == nil {
 			msgMap["data"] = goja.Null()
+		} else {
+			msgMap["data"] = rm.vm.NewArrayBuffer(msg.Data)
 		}
 		msgMap["reliable"] = msg.Reliable
 		msgMap["receiveTimeMs"] = msg.ReceiveTime
@@ -563,11 +563,15 @@ func (rm *RuntimeJavaScriptMatchCore) validateBroadcast(r *goja.Runtime, f goja.
 	var dataBytes []byte
 	data := f.Argument(1)
 	if !goja.IsUndefined(data) && !goja.IsNull(data) {
-		dataStr, ok := data.Export().(string)
-		if !ok {
-			panic(r.NewTypeError("expects data to be a string or nil"))
+		dataExport := data.Export()
+		switch dataExport.(type) {
+		case string:
+			dataBytes = []byte(dataExport.(string))
+		case goja.ArrayBuffer:
+			dataBytes = dataExport.(goja.ArrayBuffer).Bytes()
+		default:
+			panic(r.NewTypeError("expects data to be an Uint8Array, a string or nil"))
 		}
-		dataBytes = []byte(dataStr)
 	}
 
 	filter := f.Argument(2)
diff --git a/server/runtime_javascript_nakama.go b/server/runtime_javascript_nakama.go
index b7bce33d060e0468bc195b7ca977785599262d41..a482aad10c9bf102b4631f86527d5542fca1837d 100644
--- a/server/runtime_javascript_nakama.go
+++ b/server/runtime_javascript_nakama.go
@@ -39,6 +39,7 @@ import (
 	"net/http"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"github.com/dop251/goja"
 	"github.com/gofrs/uuid"
@@ -250,6 +251,42 @@ func (n *runtimeJavascriptNakamaModule) mappings(r *goja.Runtime) map[string]fun
 		"channelMessageSend":              n.channelMessageSend(r),
 		"channelMessageUpdate":            n.channelMessageUpdate(r),
 		"channeldIdBuild":                 n.channelIdBuild(r),
+		"binaryToString":                  n.binaryToString(r),
+		"stringToBinary":                  n.stringToBinary(r),
+	}
+}
+
+func (n *runtimeJavascriptNakamaModule) binaryToString(r *goja.Runtime) func(goja.FunctionCall) goja.Value {
+	return func(f goja.FunctionCall) goja.Value {
+		if goja.IsUndefined(f.Argument(0)) || goja.IsNull(f.Argument(0)) {
+			panic(r.NewTypeError("expects a Uint8Array object"))
+		}
+
+		data, ok := f.Argument(0).Export().(goja.ArrayBuffer)
+		if !ok {
+			panic(r.NewTypeError("expects a Uint8Array object"))
+		}
+
+		if !utf8.Valid(data.Bytes()) {
+			panic(r.NewTypeError("expects data to be UTF-8 encoded"))
+		}
+
+		return r.ToValue(string(data.Bytes()))
+	}
+}
+
+func (n *runtimeJavascriptNakamaModule) stringToBinary(r *goja.Runtime) func(goja.FunctionCall) goja.Value {
+	return func(f goja.FunctionCall) goja.Value {
+		if goja.IsUndefined(f.Argument(0)) || goja.IsNull(f.Argument(0)) {
+			panic(r.NewTypeError("expects a string"))
+		}
+
+		str, ok := f.Argument(0).Export().(string)
+		if !ok {
+			panic(r.NewTypeError("expects a string"))
+		}
+
+		return r.ToValue([]byte(str))
 	}
 }