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Personalization to Help Browse Safely (MDN Web Docs)

MDN’s guide to accommodating vestibular disorders and photosensitivity through user- and system-level personalization settings, distinct from fixed content-duration or flash-rate limits.

License: CC BY-SA 2.5+ (Mozilla Contributors).

Key points

  • A system-level “reduce motion” preference is a distinct accommodation from hard duration/flash-rate caps — it’s a proactive opt-out a user sets once and expects honored everywhere, not a substitute for those caps.
  • The preference doesn’t reach every kind of animation. It can affect animation the page itself controls (e.g. CSS transitions), but not a self-contained animated GIF, so a page can’t rely on it as the sole line of defense.
  • Organizations serving the public should keep at least one workstation configured with these personalization/accessibility settings on, so staff can verify what an accommodating experience actually looks like rather than assuming a design works from the default configuration alone.

Cited In

Principles

Created Fri Aug 07 2026 00:00:00 GMT+0000 (Coordinated Universal Time) Updated Fri Aug 28 2026 00:00:00 GMT+0000 (Coordinated Universal Time)