diff --git a/cmd/server/main.go b/cmd/server/main.go
index 70a46af..499f613 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -63,7 +63,7 @@ var uploadTpl = template.Must(template.New("upload").Parse(`
 <body>
   <div class="wrap">
     <h1>Gliffy → draw.io Converter</h1>
-    <p>Upload a <code>.gliffy</code> (zip) or <code>.gon</code> JSON file. Convert to <code>.drawio</code>, or open directly in diagrams.net.</p>
+    <p>Upload a <code>.gliffy</code> (zip) or <code>.gon</code> JSON file. Convert to <code>.drawio</code>, or open directly in your draw.io instance.</p>
 
     <div class="card">
       <form id="uploadForm" method="post" enctype="multipart/form-data">
@@ -73,7 +73,7 @@ var uploadTpl = template.Must(template.New("upload").Parse(`
           <div class="btnrow">
             <label class="buttonlike secondary" for="fileInput">Choose file</label>
             <button type="submit" formaction="/convert" id="downloadBtn">Download .drawio</button>
-            <button type="submit" class="linkbtn" formaction="/open" id="openBtn">Open in diagrams.net</button>
+            <button type="submit" class="linkbtn" formaction="/open" id="openBtn">Open in draw.io</button>
           </div>
           <div class="note" id="picked"></div>
         </div>
@@ -336,7 +336,9 @@ func buildDiagramsNetURL(r *http.Request, id string) string {
 	}
 	base := fmt.Sprintf("%s://%s/diagram?id=%s", scheme, r.Host, url.QueryEscape(id))
 	// Request AWS library for custom shapes (e.g., aws4) to render correctly.
-	return drawioBaseURL + "/?splash=0&ui=min&libs=aws4&url=" + url.QueryEscape(base)
+	// Provide both query parameter and fragment (#U) so self-hosted instances that prefer #U can load the file.
+	encoded := url.QueryEscape(base)
+	return fmt.Sprintf("%s/?splash=0&ui=min&libs=aws4&url=%s#U%s", drawioBaseURL, encoded, encoded)
 }
 
 func addCORS(w http.ResponseWriter) {
