Prevent Duplicate Tabs

Prevent Duplicate Tabs is a Chrome extension that blocks duplicate tabs automatically. If you open a link or URL that’s already open in another tab, it detects the duplicate and either closes it or switches you to the existing tab—so you get fewer tabs, less clutter, and lower memory use. No account, no sign-in; all settings and a local “duplicates prevented” count stay on your device. Why use a duplicate tab blocker? Opening the same page in multiple tabs wastes RAM, slows Chrome, and makes it harder to find the tab you need. A tab manager that prevents duplicate tabs keeps your browser lean: you avoid accidentally opening the same article, doc, or site twice, and you choose what happens when a duplicate is detected—close the new tab, close the old one, or switch to the right tab. Useful for researchers, developers, and anyone who keeps many tabs open. How it works When you open a new tab, the extension compares its URL to your open tabs (across all windows or only the current window—you choose). If it finds a match, it applies your chosen action right away. You can set a default behavior for all sites and override it per domain, so you can allow multiple Gmail tabs but block duplicates everywhere else. Duplicate tab detection and actions • Automatic detection – Compares new tab URLs to open tabs; no manual steps. • Four actions – Close the new duplicate and stay where you are; close the old duplicate and stay; close the new and switch to the existing tab; or close the old and switch to the new. When you switch, the correct window is focused and empty windows are closed. • All windows or current window – Check for duplicates across all Chrome windows or only in the current window. • Ignore URL parameters – Option to treat the same page with different query strings (e.g. ?id=1 vs ?id=2) as one URL, so you can block or allow duplicates based on your workflow. Exceptions and per-site rules • Exceptions list – Allow duplicate tabs for specific URLs or whole domains (e.g. allow multiple Gmail tabs or several docs). • Per-site rules – Set a different duplicate action and “ignore URL parameters” per domain from the options page. • Popup toggles – From the extension icon, turn the extension on or off, or allow duplicates for “this page only” or “this domain only” without opening options. Control and stats • Enable or disable anytime – One toggle in the popup. • Local stats – See how many tabs you have open and how many duplicates were prevented; stored on your device only. • Options page – Full control: default action, scope (all windows or current window), ignore-parameters, exceptions list, and site-specific rules. Right-click the icon → Options. Use cases and benefits • Reduce tab clutter – Stop ending up with dozens of tabs for the same site. • Save memory – Fewer duplicate tabs mean less RAM and a faster browser. • Stay focused – No confusion from multiple copies of the same page. • Different behavior per site – Block duplicates on most sites but allow multiple tabs for email, docs, or tools that need them. • No account – Install and use; all settings stay in your browser. Privacy and permissions The extension uses the tabs permission (to read tab URLs for duplicate detection and to close or switch tabs), storage (to save your settings and local “duplicates prevented” count), and windows (to focus the right window when switching and to close empty windows). It does not read page content, does not send your data to any server, and does not use analytics or tracking. See the extension privacy policy for full details.