Ultimate Brightness Control

Dim or boost any webpage from 10% to 200%. Works in fullscreen videos and iframe players too. Free.

Ultimate Brightness Control — the only browser brightness extension and screen dimmer that keeps working when a video goes fullscreen. Most extension overlays disappear when you enter fullscreen mode because the browser forces the video element to the top. Ultimate Brightness Control solves this by intelligently injecting a custom overlay directly into the fullscreen element — providing a seamless night mode and eye protection experience on YouTube, Dailymotion, Twitch, and any iframe video player. FEATURES Wide Brightness Range: Adjust brightness from 10% to 200% — perfect as a night owl dimmer to reduce eye strain during late-night browsing or to boost washed-out screens. True Fullscreen Dimming: Your screen shade stays completely active when videos enter fullscreen or inside iframe players, keeping you protected from sudden bright light. Site-Specific Settings: Set a custom brightness filter or preference for each website, saved automatically. Global Brightness Control: One master slider controls all browser tabs at once for instant, unified brightness management. Instant Real-Time Effect: Visual changes apply instantly as you drag the slider. 100% Privacy-Focused: A clean, lightweight tool built for eye protection and blue light reduction through screen dimming, with no accounts, no analytics, and zero data collection. HOW IT WORKS Click the extension icon on any page and drag the slider to your preferred brightness. Enable "Apply only to this site" to save a custom brightness setting for that specific domain. Use "Disable here" or "Disable everywhere" for instant toggles. PRIVACY This extension does not collect, store, or transmit any personal data. All settings are saved locally in your browser using Chrome's built-in storage API. No third-party analytics, no user tracking, no ads. PERMISSIONS storage — saves your brightness preferences locally. tabs — reads the current tab's URL to apply site-specific settings.