HTML Code

<!DOCTYPE html>

<html lang=en>

<head>

  <meta charset=UTF-8>

  <meta name=viewport content="width=device-width,initial-scale=1">

  <title>onstorage — addEventListener</title>

  <style>body{font-family:system-ui,sans-serif;margin:0;padding:1.5rem;background:#f8fafc;color:#334155;line-height:1.7}h1{margin:0 0 .75rem;font-size:1.25rem;color:#0f172a}#log{padding:.75rem 1rem;border-radius:8px;font-size:.8125rem;font-family:ui-monospace,monospace;max-width:520px;background:#f1f5f9;border:1px solid #e2e8f0;color:#475569;white-space:pre-wrap}.hint{font-size:.875rem;color:#64748b;max-width:520px}</style>

</head>

<body>

  <h1>addEventListener("storage", …)</h1>

  <p class=hint>Change localStorage in DevTools (Application tab) or in another tab of this page to see event details below.</p>

  <pre id=log aria-live=polite>Listening for storage events…</pre>



  <script>var log=document.getElementById("log");window.addEventListener("storage",(function(e){log.textContent="Dynamic storage handler:\nKey: "+e.key+"\nOld Value: "+e.oldValue+"\nNew Value: "+e.newValue+"\nURL: "+e.url,log.style.background="#f0fdf4",log.style.borderColor="#bbf7d0",log.style.color="#166534"}))</script>

</body>

</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

HTML onstorage Attribute — addEventListener