Run custom JavaScript on any website. Use this tool to inject custom JavaScript in any website. Your scripts are kept by the Chrome sync API and applied across domain URLs. You can inject custom JavaScript based on domain or custom Regular Expression (since v3.1.1). This extension supports dedicated tab to edit your codes since v2.5.1 You can use some built-in libraries such as * jQuery 1.12.4 * jQuery 2.2.4 * jQuery 3.2.1 * Indefinite Observable 1.0.1 * MooTools 1.6.0 or/and your own external scripts. Use cases: * Site debugging (wrong list sort, etc.) * Extract useful information from website, such as billings/orders metadata * Hide annoying popups and Ads * Custom UI * Anything you can think of :) Inject large JavaScript: https://github.com/xcv58/Custom-JavaScript-for-Websites-2#how-do-i-inject-large-javascript New features: Ace Editor (formating, highlight, undo/redo by hotkeys) Draft auto save (so doesn't matter when you close the window without saving) Hosts (websites) switch (you can browse customjs of other websites) Include external script (eq. Underscore.js is cool) Thanks to: Ace - http://ace.c9.io/ Pure - http://purecss.io/