diff --git a/lib/converterlist/ConverterList.h b/lib/converterlist/ConverterList.h
index ac0d5d0..afd776e 100644
--- a/lib/converterlist/ConverterList.h
+++ b/lib/converterlist/ConverterList.h
@@ -13,7 +13,8 @@ public:
     typedef void (*LConverter)(const Msg &msg, T *);
 
 private:
-    double dummy;
+    String keyList;
+    bool keyListFilled=false;
     class ConverterEntry
     {
     public:
@@ -44,7 +45,7 @@ private:
     typedef std::map<String, ConverterEntry> ConverterMap;
     ConverterMap converters;
 
-public:
+    public:
     /**
         *  register a converter
         *  each of the converter functions must be registered in the constructor 
@@ -54,70 +55,82 @@ public:
         unsigned long *lpgn=new unsigned long[1]{pgn};
         ConverterEntry e(1,lpgn, converter);
         converters[String(pgn)] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, LConverter converter)
     {
         unsigned long *lpgn=new unsigned long[1]{pgn};
         ConverterEntry e(1,lpgn, converter);
         converters[String(pgn)] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, String sentence, Converter converter)
     {
         unsigned long *lpgn=new unsigned long[1]{pgn};
         ConverterEntry e(1,lpgn, converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, String sentence, LConverter converter)
     {
         unsigned long *lpgn=new unsigned long[1]{pgn};
         ConverterEntry e(1,lpgn, converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(int num,unsigned long *lpgn, String sentence, Converter converter)
     {
         ConverterEntry e(num,lpgn, converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(int num,unsigned long *lpgn, String sentence, LConverter converter)
     {
         ConverterEntry e(num,lpgn, converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, unsigned long pgn2, String sentence, Converter converter)
     {
         unsigned long *lpgn=new unsigned long[2]{pgn,pgn2};
         ConverterEntry e(2, lpgn, converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, unsigned long pgn2, String sentence, LConverter converter)
     {
         unsigned long *lpgn=new unsigned long[2]{pgn,pgn2};
         ConverterEntry e(2, lpgn, converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, unsigned long pgn2, unsigned long pgn3,String sentence, Converter converter)
     {
         unsigned long *lpgn=new unsigned long[3]{pgn,pgn2,pgn3};
         ConverterEntry e(3, lpgn,converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, unsigned long pgn2, unsigned long pgn3,String sentence, LConverter converter)
     {
         unsigned long *lpgn=new unsigned long[3]{pgn,pgn2,pgn3};
         ConverterEntry e(3, lpgn,converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, unsigned long pgn2, unsigned long pgn3,unsigned long pgn4,String sentence, Converter converter)
     {
         unsigned long *lpgn=new unsigned long[4]{pgn,pgn2,pgn3,pgn4};
         ConverterEntry e(4, lpgn,converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
     void registerConverter(unsigned long pgn, unsigned long pgn2, unsigned long pgn3,unsigned long pgn4,String sentence, LConverter converter)
     {
         unsigned long *lpgn=new unsigned long[4]{pgn,pgn2,pgn3,pgn4};
         ConverterEntry e(4, lpgn,converter);
         converters[sentence] = e;
+        keyListFilled=false;
     }
 
     bool handleMessage(String code, const Msg &msg, T *base)
@@ -182,5 +195,18 @@ public:
             json[prefix][String(it->first)] = it->second.count;
         }
     }
+    String handledKeys(){
+        if (! keyListFilled){
+            keyList=String();
+            bool first=true;
+            for (auto it=converters.begin();it != converters.end();it++){
+                if (! first) keyList.concat(',');
+                first=false;
+                keyList.concat(it->first);
+            }
+            keyListFilled=true;
+        }
+        return keyList;
+    }
 };
 #endif
\ No newline at end of file
diff --git a/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp b/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp
index f54db57..741df73 100644
--- a/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp
+++ b/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp
@@ -402,6 +402,9 @@ public:
     virtual int numConverters(){
         return converters.numConverters();
     }
+    virtual String handledKeys(){
+        return converters.handledKeys();
+    }
 
     NMEA0183DataToN2KFunctions(GwLog *logger, GwBoatData *boatData, N2kSender callback)
         : NMEA0183DataToN2K(logger, boatData, callback)
diff --git a/lib/nmea0183ton2k/NMEA0183DataToN2K.h b/lib/nmea0183ton2k/NMEA0183DataToN2K.h
index b2df5f1..bb6255e 100644
--- a/lib/nmea0183ton2k/NMEA0183DataToN2K.h
+++ b/lib/nmea0183ton2k/NMEA0183DataToN2K.h
@@ -16,6 +16,7 @@ class NMEA0183DataToN2K{
         virtual bool parseAndSend(const char *buffer, int sourceId);
         virtual unsigned long *handledPgns()=0;
         virtual int numConverters()=0;
+        virtual String handledKeys()=0;
         static NMEA0183DataToN2K* create(GwLog *logger,GwBoatData *boatData,N2kSender callback);
 };
 #endif
\ No newline at end of file
diff --git a/lib/nmea2kto0183/N2kDataToNMEA0183.cpp b/lib/nmea2kto0183/N2kDataToNMEA0183.cpp
index 53d687d..04b2860 100644
--- a/lib/nmea2kto0183/N2kDataToNMEA0183.cpp
+++ b/lib/nmea2kto0183/N2kDataToNMEA0183.cpp
@@ -92,6 +92,9 @@ private:
         logger->logString("CONV: # %d handled PGNS", converters.numConverters());
         return converters.handledPgns();
     }
+    virtual String handledKeys(){
+        return converters.handledKeys();
+    }
     virtual void HandleMsg(const tN2kMsg &N2kMsg)
     {
         String key=String(N2kMsg.PGN);
diff --git a/lib/nmea2kto0183/N2kDataToNMEA0183.h b/lib/nmea2kto0183/N2kDataToNMEA0183.h
index 6b2f221..339d32a 100644
--- a/lib/nmea2kto0183/N2kDataToNMEA0183.h
+++ b/lib/nmea2kto0183/N2kDataToNMEA0183.h
@@ -51,5 +51,6 @@ public:
   virtual unsigned long* handledPgns()=0;
   virtual int numPgns()=0;
   virtual void toJson(JsonDocument &json)=0;
+  virtual String handledKeys()=0;
 };
 #endif
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 3558505..821c49f 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -12,7 +12,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#define VERSION "0.5.1"
+#define VERSION "0.5.2"
 
 // #define GW_MESSAGE_DEBUG_ENABLED
 // #define FALLBACK_SERIAL
@@ -189,6 +189,21 @@ class CapabilitiesRequest : public GwRequestMessage{
       serializeJson(json,result);
     }  
 };
+class ConverterInfoRequest : public GwRequestMessage{
+  public:
+    ConverterInfoRequest() : GwRequestMessage(F("application/json"),F("converterInfo")){};
+  protected:
+    virtual void processRequest(){
+      DynamicJsonDocument json(512);
+      String keys=toN2KConverter->handledKeys();
+      logger.logDebug(GwLog::DEBUG,"handled nmea0183: %s",keys.c_str());
+      json["nmea0183"]=keys;
+      keys=nmea0183Converter->handledKeys();
+      logger.logDebug(GwLog::DEBUG,"handled nmea2000: %s",keys.c_str());
+      json["nmea2000"]=keys;
+      serializeJson(json,result);
+    }  
+};
 class ConfigRequest : public GwRequestMessage
 {
 public:
@@ -346,6 +361,9 @@ void setup() {
   webserver.registerMainHandler("/api/capabilities", [](AsyncWebServerRequest *request)->GwRequestMessage *{
     return new CapabilitiesRequest();
   });
+  webserver.registerMainHandler("/api/converterInfo", [](AsyncWebServerRequest *request)->GwRequestMessage *{
+    return new ConverterInfoRequest();
+  });
   webserver.registerMainHandler("/api/status", [](AsyncWebServerRequest *request)->GwRequestMessage *
                               { return new StatusRequest(); });
   webserver.registerMainHandler("/api/config", [](AsyncWebServerRequest *request)->GwRequestMessage *
diff --git a/web/index.html b/web/index.html
index 6df2586..4ab47bd 100644
--- a/web/index.html
+++ b/web/index.html
@@ -146,9 +146,16 @@
       }
     }
   }
-  function showOverlay(text){
+  function showOverlay(text,isHtml){
     let el=document.getElementById('overlayContent');
-    el.textContent=text;
+    if (isHtml){
+      el.innerHTML=text;
+      el.classList.remove("text");
+    }
+    else{
+      el.textContent=text;
+      el.classList.add("text");
+    }
     let container=document.getElementById('overlayContainer');
     container.classList.remove('hidden');
   }
@@ -282,7 +289,10 @@
                 labelEl.classList.add('label');
                 labelEl.textContent = label;
                 row.appendChild(labelEl);
-                let valueEl = createInput(item,row);
+                let valueFrame=document.createElement("div");
+                valueFrame.classList.add("value");
+                row.appendChild(valueFrame);
+                let valueEl = createInput(item,valueFrame);
                 if (!valueEl) return;
                 valueEl.setAttribute('data-default', item.default);
                 valueEl.addEventListener('change', function (ev) {
@@ -290,6 +300,9 @@
                   checkChange(el,row);
                 })
                 if (item.check) valueEl.setAttribute('data-check', item.check);
+                let btContainer=document.createElement("div");
+                btContainer.classList.add("buttonContainer");
+                row.appendChild(btContainer);
                 let bt = document.createElement('button');
                 bt.classList.add('defaultButton');
                 bt.setAttribute('data-default', item.default);
@@ -299,14 +312,14 @@
                   valueEl.dispatchEvent(changeEvent);
                 })
                 bt.textContent = "X";
-                row.appendChild(bt);
+                btContainer.appendChild(bt);
                 bt = document.createElement('button');
                 bt.classList.add('infoButton');
                 bt.addEventListener('click', function (ev) {
                   showOverlay(item.description);
                 });
                 bt.textContent = "?";
-                row.appendChild(bt);
+                btContainer.appendChild(bt);
                 frame.appendChild(row);
               })
               resetForm();
@@ -314,6 +327,18 @@
         })
         .catch(function (err) { alert("unable to load config: " + err) })
     }
+  function converterInfo(){
+    getJson("api/converterInfo").then(function(json){
+      let text="<h3>Converted entities</h3>";
+      text+="<p><b>NMEA0183 to NMEA2000:</b><br/>";
+      text+="   "+(json.nmea0183||"").replace(/,/g,", ");
+      text+="</p>";
+      text+="<p><b>NMEA2000 to NMEA0183:</b><br/>";
+      text+="   "+(json.nmea2000||"").replace(/,/g,", ");
+      text+="</p>";
+      showOverlay(text,true);
+    });
+  }  
   window.setInterval(update,1000);
   window.addEventListener('load',function(){
   let buttons=document.querySelectorAll('button');
@@ -348,6 +373,11 @@ span.label {
     display: inline-block;
     opacity: 0.6;
 }
+.value {
+    width: 19em;
+    display: flex;
+    flex-direction: row;
+}
 span#connected {
     display: inline-block;
     background-color: red;
@@ -360,6 +390,9 @@ span#connected.ok{
 }
 .row {
     margin: 0.5em;
+    display: flex;
+    flex-direction: row;
+    flex-wrap: wrap;
 }
 .filter {
     display: inline-block;
@@ -394,10 +427,14 @@ div#overlay {
     margin: auto;
     background-color: white;
     padding: 0.5em;
+    max-width: 100%;
+    box-sizing: border-box;
 }
 div#overlayContent {
     padding: 0.5em;
-    white-space: pre;
+}
+div#overlayContent.text{
+  white-space: pre;
 }
 .overlayButtons {
     border-top: 1px solid grey;
@@ -414,6 +451,7 @@ div#overlayContent {
 <div class="row">
   <span class="label">VERSION</span>
   <span class="value" id="version">---</span>
+  <button class="infoButton" id="converterInfo">?</button> 
 </div>
 <div class="row">
   <span class="label">connected</span>