Block Superwhite Abuse

Clamps HDR page content to standard brightness, neutralizing blinding 'superwhite' avatars, images and videos on HDR displays.

People have started uploading "superwhite" profile pictures and images — tiny HDR videos and HDR AVIF files crafted to render far brighter than white on HDR displays (recent MacBooks, iPhones and HDR monitors). Somewhere between distracting and physically painful, they follow you around every comment thread they appear in. This extension neutralizes them. It applies the CSS property dynamic-range-limit: standard to every page, capping all content at standard-dynamic-range brightness. HDR abuse renders as ordinary white. Normal (SDR) content — which is virtually everything — is pixel-for-pixel unaffected, so there are no false positives, ever. Notable properties: • No JavaScript. The entire extension is one static stylesheet. • Collects nothing, stores nothing, contacts no servers. • Works in every frame, and reaches shadow-DOM UIs (Reddit, YouTube) through CSS inheritance. • Legitimate HDR photos and videos still display — just at standard brightness. Free and open source: https://github.com/intUnderflow/block-superwhite-abuse