demo · v134

Document Subtitle

<meta name="document-subtitle"> gives PWAs a stable app title plus a transient subtitle slot. Window decorations and OS task switchers can show the app name without losing the dynamic state. Edit either field below; the simulated installed-app titlebar updates immediately.

probing meta name="document-subtitle"...

Try it

simulated installed PWA titlebar:

Inbox — 2 unread

document.title also updates in the browser tab.

The code

<head>
  <title>Inbox</title>
  <meta name="document-subtitle" content="2 unread">
</head>
<script>
  // Updating the subtitle without touching the stable app title:
  document.querySelector('meta[name="document-subtitle"]')
          .setAttribute('content', '5 unread');
</script>

see also