diff --git a/dev/ucsc/slowHub.html b/dev/ucsc/slowHub.html
index 31f50510d..29bcc4dc3 100644
--- a/dev/ucsc/slowHub.html
+++ b/dev/ucsc/slowHub.html
@@ -31,6 +31,7 @@
     //igvConfig.reference.chromAliasBbURL = undefined   // TODO <- chromAliasBB is slowish
 
     const browser = await igv.createBrowser(document.getElementById('igvDiv'), igvConfig)
+      console.log(browser.getTrackURLs())
 
 
 </script>
diff --git a/js/browser.js b/js/browser.js
index e568148c8..640273008 100755
--- a/js/browser.js
+++ b/js/browser.js
@@ -1256,6 +1256,7 @@ class Browser {
         return this.trackViews.filter(tv => tv.track && tv.track.name).map(tv => tv.track.name)
     }
 
+
     /**
      * NOTE: Public API function
      *
@@ -1338,6 +1339,14 @@ class Browser {
         return this.trackViews.map(tv => tv.track).filter(t => t !== undefined)
     }
 
+
+    getTrackURLs() {
+        return new Set(this.tracks
+            .filter(track => track.config && StringUtils.isString(track.config.url))
+                .map(track => track.config.url))
+    }
+
+
     /**
      * Set the track height globally for all tracks.  (Note: Its not clear why this is useful).
      * @param newHeight