TweakJS

Execute custom JavaScript on Websites

Run custom JavaScript on any site — per-domain tweaks to change appearance, replace text, redirect pages, and more. TweakJS is a lightweight extension that gives you full control over what runs on the pages you visit. Add domains and attach JavaScript snippets that execute automatically whenever those pages load. Use it to personalize site appearance, fix small annoyances, automate tiny tasks, or prototype quick changes — all from your browser. Why TweakJS? Powerful and flexible: from cosmetic changes and text replacements to redirects and small automations. Designed for power users and web tinkerers who want fast, on-the-fly control over what runs on the pages they visit. Typical use cases Change fonts, spacing or colors on frequently visited sites to improve readability. Remove distracting elements (headers, sidebars, popups). Replace specific words or phrases across a page. Redirect a site to a preferred URL automatically. Inject small utility features (quick info panels, debug helpers, shortcuts). Safety & privacy TweakJS executes JavaScript in the context of the web pages you visit. This is powerful but also sensitive. Only install scripts from sources you trust. TweakJS — small scripts, big control. Customize the web the way you want it. Author: P.C