Cross-Browser Duplicate Tab Guard

Prevent duplicate tabs across Chrome, Brave, and Chromium. Coordinates open URLs locally with customizable domain exceptions.

Cross-Browser Duplicate Tab Guard coordinates open tab state across Google Chrome, Brave, and Chromium, preventing accidental duplicate tabs across multiple windows and browsers. When you navigate to a URL that is already open in another window or browser, Tab Guard intercepts the navigation and presents an elegant, non-intrusive in-page modal informing you where the pre-existing tab is located (e.g., "Already open in Brave"). You can choose to instantly jump to the existing tab, keep the new tab open, or exclude the domain from future checks. KEY FEATURES: • Cross-Browser Coordination: Synchronizes tab states across Chrome, Brave, and Chromium via a lightweight local native messaging daemon. • Responsive Current Tab Reference: Instant focus-preserving status displays active window and tab context with one-click diagnostic copying. • Closed Shadow DOM Dialogs: In-page duplicate modals use isolated closed Shadow DOM containers to prevent website style bleed or script interference. • Powerful Exception Engine: Easily whitelist websites by exact URL, domain, wildcard, or regular expression with in-memory memoized matching. • Local-First & Zero Telemetry: 100% of coordination occurs locally on your machine over Unix domain sockets and loopback WebSockets (127.0.0.1). Zero remote telemetry, zero tracking, and no external server requests. • Incognito & Private Support: Split context support allows private tabs to be managed safely without leaking browsing history across profiles. SETUP: 1. Load this extension in your Chromium-based browser(s). 2. Run the lightweight local companion coordinator daemon. 3. Enjoy duplicate-free browsing across your entire desktop workflow!