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MIT · Firefox add-on

webext-gmeet-unmirror

Hides the Google Meet presentation tile so full-screen sharing doesn't produce an infinite hall of mirrors.

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Features

  • Hall-of-mirrors fix — when you share your whole screen on a Meet call, the presentation tile is hidden so it stops feeding back into itself
  • One-click toggle — a floating button on the Meet page hides or reveals the presentation tile on demand
  • Alt+Shift+H shortcut — toggle without reaching for the mouse; it stays inert while typing in chat or any input field
  • Auto-hide on share — detects when a shared screen is dominating the call and hides the tile itself, no click needed
  • Manual override wins — bring the tile back and it stays visible for the rest of that presentation, even with auto-hide on
  • Nothing else touched — the participant grid and your own self-view thumbnail are never hidden, only the mirrored copy of your own screen

Install

Two ways in — pick whichever suits you:

From Firefox Add-ons (remote)

gmeet-unmirror on addons.mozilla.org — one click, and Firefox keeps it updated. (The listing goes live once the add-on clears AMO review.)

From source (local)

Build it from this repo and load it into Firefox yourself:

git clone https://github.com/kud/webext-gmeet-unmirror.git
cd webext-gmeet-unmirror
npm install
npm run build   # → web-ext-artifacts/gmeet-unmirror-<version>.zip

Then open about:debugging#/runtime/this-firefox, click Load Temporary Add-on, and select manifest.json (or the built zip). Firefox removes temporary add-ons on restart, so this is the quick local route; for a permanent unsigned install you'd need Firefox Developer Edition or Nightly with signature enforcement off.

Usage

Once installed, open any Google Meet call and share your whole screen as usual:

  1. A Hide presentation button appears bottom-right on the page — click it, or press Alt+Shift+H, to hide the presentation tile and replace it with a small placeholder.
  2. Press the shortcut (or click the button, now reading Show presentation) again to bring it back.
  3. With auto-hide, gmeet-unmirror hides the tile itself as soon as a shared screen dominates the call — no click required. Overriding it manually keeps your choice in effect until the presentation ends.

The extension only ever touches the presentation tile: the participant grid and your self-view stay exactly as they are.

Development

git clone https://github.com/kud/webext-gmeet-unmirror.git
cd webext-gmeet-unmirror
npm install
npm run dev

npm run dev runs web-ext run --firefox=nightly, which launches Firefox Nightly with the extension already loaded and reloads it on every save to src/content.js.

(For a one-off manual load without the dev server, see Install → From source above.)

Other scripts:

npm run lint    # web-ext lint
npm run build   # bundle into web-ext-artifacts/

The extension has a single host permission, *://meet.google.com/*, no background worker, and makes no network requests of its own — everything runs in the content script injected into the Meet tab.