Adjust the brightness of the current page only using a simple slider from the extension popup. Brightness is per-tab and remembered while the tab stays open.
- Per-tab brightness control (0%–200% internally; slider shows 0%–100%).
- Applies instantly without reloading the page.
- Resets to normal when the tab is closed.
- One-click Reset button to return to 100%.
- When you open the popup (activeTab), the extension programmatically injects a small content script into the current tab using
chrome.scripting. - The content script adds a CSS rule:
html { filter: brightness(var(--browser-dimmer-brightness, 1)) !important; }and updates a CSS variable. - The popup slider sends updates to the background, which stores brightness per tab and notifies the content script to apply it.
- Open Chrome and go to
chrome://extensions. - Enable "Developer mode" (top-right).
- Click "Load unpacked" and select this folder.
- Pin the extension (optional), then click its icon to adjust brightness on the current tab.
- Some pages do not allow extensions to run content scripts; brightness will not apply there. The extension detects this by attempting to inject on popup open and will disable controls with an explanatory message (no hardcoded URL list).
- Existing tabs opened before installation may require a refresh to activate the content script.
- Default brightness is 100% (no change). The extension supports up to 200% internally to allow potential brightening; the popup shows 0–100% by default.
manifest.json— MV3 manifestbackground.js— service worker holding per-tab state and messaging- Toolbar icon is a monochrome line drawing (#a8a9a9 on #202121) generated at multiple sizes. It dims on restricted pages.
content.js— injects and updates the brightness CSS on pagespopup.html,popup.js,popup.css— slider UI and logic- Includes a Reset button (☀️) to jump to 100%
- Source SVGs:
icons/backlight.svg(toolbar) andicons/reset.svg(popup button) - Pre-generated PNGs used by the manifest live in
icons/generated/. No build step is required.