diff --git a/node-api/public/index.html b/node-api/public/index.html
index b2e61ec..7025b8b 100644
--- a/node-api/public/index.html
+++ b/node-api/public/index.html
@@ -106,11 +106,29 @@ btnClear.addEventListener('click', async () => {
 });
 
 btnCopy.addEventListener('click', async () => {
+  const text = JSON.stringify(history, null, 2);
   try {
-    await navigator.clipboard.writeText(JSON.stringify(history, null, 2));
+    async function copyText(t) {
+      if (navigator.clipboard && navigator.clipboard.writeText) {
+        return navigator.clipboard.writeText(t);
+      }
+      const ta = document.createElement('textarea');
+      ta.value = t;
+      ta.style.position = 'fixed';
+      ta.style.opacity = '0';
+      ta.setAttribute('readonly', '');
+      document.body.appendChild(ta);
+      ta.focus();
+      ta.select();
+      ta.setSelectionRange(0, ta.value.length);
+      const ok = document.execCommand('copy');
+      document.body.removeChild(ta);
+      if (!ok) throw new Error('copy command failed');
+    }
+    await copyText(text);
     alert('Copiado al portapapeles');
   } catch (e) {
-    alert('No se pudo copiar: ' + e.message);
+    alert('No se pudo copiar: ' + (e && e.message ? e.message : e));
   }
 });