I like motion on websites. Hover states, page transitions, the small interactions people actually design. I do not want that in macOS. The dock, Mission Control, and the rest of the system chrome feel better with Reduce Motion on.
So the OS setting stays on, and this toggle tells the browser that pages should see prefers-reduced-motion: no-preference.
No popup, no settings page. A few kilobytes.
| Icon | Color | What pages see |
|---|---|---|
| Play | Purple | prefers-reduced-motion: no-preference |
| Pause | Gray | Whatever the OS reports. Reloads this tab only. |
Other tabs stay put until you refresh them.
Chrome, Edge, Brave, and Arc on version 121 or newer.
- Open
chrome://extensions - Turn on Developer mode
- Load unpacked and pick this folder
Firefox 128 or newer.
- Open
about:debugging#/runtime/this-firefox - Load Temporary Add-on
- Choose
manifest.json
Note
A temporary Firefox add-on is gone the next time you quit the browser. Load it again from this folder, or sign it through addons.mozilla.org if you want it to stick.
Tip
After install, open check.html. Both the JS line and the CSS line should say MOTION OK while the toggle is on.
Important
file:// pages only see the script if you allow the extension access to file URLs. Chrome puts that toggle on the extension's details page.
Chrome runs background.js as a Manifest V3 service worker. Firefox uses the same file as an event page. MDN documents that split: both service_worker and scripts live in the manifest, and each browser picks the one it supports.
What the injected script changes
With the toggle on, inject.js starts in the page's main world before the site's own scripts:
matchMedia('(prefers-reduced-motion: …)')reports no preference@media (prefers-reduced-motion)rules the script can read get rewritten so the reduce branch does not apply
Warning
Stylesheets from another origin that hide cssRules stay untouched. Same-origin CSS and most JS motion libraries are covered.
Nothing is sent anywhere. The only stored value is a boolean in chrome.storage.local. Firefox also declares data_collection_permissions as none.
