diff --git a/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js b/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js
index 1ea5445ce..3eb9d0516 100644
--- a/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js
+++ b/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js
@@ -20,7 +20,30 @@ module.exports = function(RED) {
     var isUtf8 = require('is-utf8');
     var HttpsProxyAgent = require('https-proxy-agent');
     var url = require('url');
-
+    const knownMediaTypes = {
+        "text/css":"string",
+        "text/html":"string",
+        "text/plain":"string",
+        "text/html":"string",
+        "application/json":"object",
+        "application/octet-stream":"buffer",
+        "application/pdf":"buffer",
+        "application/x-gtar":"buffer",
+        "application/x-gzip":"buffer",
+        "application/x-tar":"buffer",
+        "application/xml":"string",
+        "application/zip":"buffer",
+        "audio/aac":"buffer",
+        "audio/ac3":"buffer",
+        "audio/basic":"buffer",
+        "audio/mp4":"buffer",
+        "audio/ogg":"buffer",
+        "image/bmp":"buffer",
+        "image/gif":"buffer",
+        "image/jpeg":"buffer",
+        "image/tiff":"buffer",
+        "image/png":"buffer",
+    }
     //#region "Supporting functions"
     function matchTopic(ts,t) {
         if (ts == "#") {
@@ -188,24 +211,7 @@ module.exports = function(RED) {
      */
     function subscriptionHandler(node, datatype ,topic, payload, packet) {
         const v5 = node.brokerConn.options && node.brokerConn.options.protocolVersion == 5;
-
-        if (datatype === "buffer") {
-            // payload = payload;
-        } else if (datatype === "base64") {
-            payload = payload.toString('base64');
-        } else if (datatype === "utf8") {
-            payload = payload.toString('utf8');
-        } else if (datatype === "json") {
-            if (isUtf8(payload)) {
-                payload = payload.toString();
-                try { payload = JSON.parse(payload); }
-                catch(e) { node.error(RED._("mqtt.errors.invalid-json-parse"),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; }
-            }
-            else { node.error((RED._("mqtt.errors.invalid-json-string")),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; }
-        } else {
-            if (isUtf8(payload)) { payload = payload.toString(); }
-        }
-        var msg = {topic:topic, payload:payload, qos:packet.qos, retain:packet.retain};
+        var msg = {topic:topic, payload:null, qos:packet.qos, retain:packet.retain};
         if(v5 && packet.properties) {
             setStrProp(packet.properties, msg, "responseTopic");
             setBufferProp(packet.properties, msg, "correlationData");
@@ -215,6 +221,58 @@ module.exports = function(RED) {
             setStrProp(packet.properties, msg, "reasonString");
             setUserProperties(packet.properties.userProperties, msg);
         }
+        const v5isUtf8 = v5 ? msg.payloadFormatIndicator === true : null;
+        const v5HasMediaType = v5 ? !!msg.contentType : null;
+        const v5MediaTypeLC = v5 ? (msg.contentType + "").toLowerCase() : null;
+
+        if (datatype === "buffer") {
+            // payload = payload;
+        } else if (datatype === "base64") {
+            payload = payload.toString('base64');
+        } else if (datatype === "utf8") {
+            payload = payload.toString('utf8');
+        } else if (datatype === "json") {
+            if (v5isUtf8 || isUtf8(payload)) {
+                try {
+                    payload = JSON.parse(payload.toString()); 
+                }
+                catch(e) { 
+                    node.error(RED._("mqtt.errors.invalid-json-parse"),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; 
+                }
+            }
+            else { node.error((RED._("mqtt.errors.invalid-json-string")),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; }
+        } else {
+            //auto
+            if(v5isUtf8 || v5HasMediaType) {
+                const outputType = knownMediaTypes[v5MediaTypeLC]
+                switch (outputType) {
+                    case "string":
+                        payload = payload.toString();
+                        break;
+                    case "buffer":
+                        //no change
+                        break;
+                    case "object":
+                        try {
+                            payload = JSON.parse(payload.toString()); 
+                        }
+                        catch(e) { 
+                            node.error(RED._("mqtt.errors.invalid-json-parse"),{payload:payload, topic:topic, qos:packet.qos, retain:packet.retain}); return; 
+                        }
+                        break;
+                    default:
+                        if (v5isUtf8 || isUtf8(payload)) { 
+                            payload = payload.toString(); //auto String
+                        }
+                        break;
+                }
+            } else if (isUtf8(payload)) { 
+                payload = payload.toString(); //auto String
+            } //else { 
+                //leave as buffer
+            //}
+        }
+        msg.payload = payload;
         if ((node.brokerConn.broker === "localhost")||(node.brokerConn.broker === "127.0.0.1")) {
             msg._topic = topic;
         }