diff --git a/share/emscripten/gpac.html b/share/emscripten/gpac.html
index efa8611108..9c5e5bbd2d 100644
--- a/share/emscripten/gpac.html
+++ b/share/emscripten/gpac.html
@@ -483,7 +483,10 @@ <h4>Performances</h4>
       let fs_steps = 20;
       let FS = null;
       
-      const STATIC_SRC = `${window.location.origin}/data`;
+      let STATIC_SRC;
+      if (window.location.origin.indexOf('.gpac.io')>0) STATIC_SRC = `${window.location.origin}/data`;
+      else if (window.location.origin.startsWith('http://')) STATIC_SRC = 'http://wasm.gpac.io/data';
+      else STATIC_SRC = 'https://wasm.gpac.io/data';
 
       const examples = [
         {
@@ -528,14 +531,6 @@ <h4>Performances</h4>
         setCommand(item.cmd.trim());
       };
 
-      async function toggle_threading() {
-        if (LIBGPAC.has_threads()){
-          
-        }
-        // if GPAC is running, abort
-        // unload current GPAC
-      }
-
       function setCommand(value) {
         cmdElement.value = value == '' ? null : value;
       };
@@ -2373,6 +2368,23 @@ <h4>Performances</h4>
         }
       }
 
+      function check_threading() {
+        const threaded = LIBGPAC.has_threads;
+        const threadedOnly = [...document.getElementsByClassName('threaded')];
+        threadedOnly.forEach(el => el.hidden = !threaded);
+        const thStatus = document.getElementById('threading_status');
+
+        threadingElement.checked = threaded;
+        if (window.location.href.indexOf('.gpac.io')<0) {
+          threadingElement.disabled = true;
+        } else {
+          threadingElement.onchange = () => {
+            const hostname = threaded ? 'wasm.gpac.io' : 'wasmth.gpac.io';
+            window.location.href = `https://${hostname}/`;
+            console.log('Reloading to ' + window.location.href);
+          }
+        }
+      }
       const LIBGPAC = {
         preRun: [
           // function() { LIBGPAC.ENV.SDL_EMSCRIPTEN_KEYBOARD_ELEMENT = "#canvas"; }
@@ -2481,6 +2493,7 @@ <h4>Performances</h4>
               load_history();
             }
           });
+          check_threading();
 
           onGpacReady();
         },
@@ -2549,17 +2562,6 @@ <h4>Performances</h4>
         libgpac(LIBGPAC);
 
       });
-      document.addEventListener('readystatechange', function() {
-        const threaded = window.location.hostname == 'wasmth.gpac.io';
-        const threadedOnly = [...document.getElementsByClassName('threaded')];
-        threadedOnly.forEach(el => el.hidden = !threaded);
-        threadingElement.checked = threaded;
-        threadingElement.onchange = () => {
-          const hostname = threaded ? 'wasm.gpac.io' : 'wasmth.gpac.io'; 
-          window.location.href = `https://${hostname}/`; 
-          console.log(hostname);
-        }
-      });
     </script>
 
   </body>
diff --git a/src/utils/os_config_init.c b/src/utils/os_config_init.c
index a19fe59f8f..551624afff 100644
--- a/src/utils/os_config_init.c
+++ b/src/utils/os_config_init.c
@@ -1382,15 +1382,17 @@ GF_Err gf_opts_save()
 
 #include <gpac/main.h>
 
+#ifdef GPAC_CONFIG_EMSCRIPTEN
+#define LOGFILE_HELP	"set output log file - use `console` for browser console"
+#else
+#define LOGFILE_HELP	"set output log file"
+#endif
+
 GF_GPACArg GPAC_Args[] = {
  GF_DEF_ARG("tmp", NULL, "specify directory for temporary file creation instead of OS-default temporary file management", NULL, NULL, GF_ARG_STRING, 0),
  GF_DEF_ARG("noprog", NULL, "disable progress messages", NULL, NULL, GF_ARG_BOOL, GF_ARG_HINT_ADVANCED|GF_ARG_SUBSYS_LOG),
  GF_DEF_ARG("quiet", NULL, "disable all messages, including errors", NULL, NULL, GF_ARG_BOOL, GF_ARG_HINT_ADVANCED|GF_ARG_SUBSYS_LOG),
- GF_DEF_ARG("log-file", "lf", "set output log file"
-#ifdef GPAC_CONFIG_EMSCRIPTEN
-			" - use `console` for browser console log"
-#endif
-		, NULL, NULL, GF_ARG_STRING, GF_ARG_SUBSYS_LOG),
+ GF_DEF_ARG("log-file", "lf", LOGFILE_HELP, NULL, NULL, GF_ARG_STRING, GF_ARG_SUBSYS_LOG),
  GF_DEF_ARG("log-clock", "lc", "log time in micro sec since start time of GPAC before each log line except for `app` tool", NULL, NULL, GF_ARG_BOOL, GF_ARG_SUBSYS_LOG),
  GF_DEF_ARG("log-utc", "lu", "log UTC time in ms before each log line except for `app` tool", NULL, NULL, GF_ARG_BOOL, GF_ARG_SUBSYS_LOG),
  GF_DEF_ARG("logs", NULL, "set log tools and levels.  \n"