PageHalo

Add colored borders to pages based on their domain or URL. Visually distinguish your environments at a glance.

PageHalo — Color borders by domain or URL Instantly tell which environment you're on. PageHalo draws a colored inset border around the browser viewport based on the domain — or specific page path — you're visiting. Perfect for distinguishing production from staging, or keeping multiple projects visually separate at a glance. FEATURES - Domain rules: Assign a color to any domain (e.g., github.com → green, localhost → red). All pages on that domain share the same border. - URL rules: Assign a different color to a specific path (e.g., github.com/myorg → blue). URL rules always win over domain rules, so two pages on the same domain can have different colors. - "This page" / "This domain" buttons: One click fills the input with the current page's full path or just its hostname — no typing needed. - Per-rule border thickness: Each rule has its own thickness slider (1–12px) so critical environments can stand out more. - Non-intrusive border: A colored inset border that doesn't affect page layout or block clicks. - Inline editing: Click any rule's color dot, label, or thickness slider to edit it on the spot. - Enable / Disable: Pause all borders instantly with the power button in the header. The header turns gray so you always know the state. Rules are preserved. - Light / Dark theme: The popup follows your preference and remembers it. - Import / Export: Copy your full config as JSON and paste it into another browser or share it with your team. - Live updates: Borders appear and disappear instantly as you add, edit, or remove rules — no page reload required. - Synced across devices: All rules are stored in Chrome Sync and follow you wherever you're signed in. HOW IT WORKS 1. Click the PageHalo icon in the toolbar. 2. Press "This page" (fills the current URL path) or "This domain" (fills just the hostname). 3. Pick a color and adjust the thickness. 4. Hit + to save. Done — the border appears immediately. USE CASES - Dev environments: Green for localhost, yellow for staging, red for production. Thicker border on prod so you never mistake it. - URL-level rules: Color github.com/myorg differently from the rest of github.com so you always know which org's repos you're browsing. - Client projects: Different color per client domain so you always know whose site you're working on. - Focus zones: Color-code work domains vs. personal browsing. PRIVACY PageHalo does not collect, transmit, or store any personal data. All rules are saved locally via Chrome Sync storage and never leave your browser. No analytics, no tracking, no network requests. See our full privacy policy for details.