Originally developed by Jan Biniok, Tampermonkey is a donationware userscript manager that was first released in May 2010. Today, Tampermonkey is a browser extension used by over 10 million users that allows them to add JavaScript scripts created by others that can modify and change how web pages work.

Browser extension, Greasemonkey, Internet terms, JavaScript, Script, Userscript

Tampermonkey is available for Chrome, Microsoft Edge, Safari, Firefox, and Opera.

  • How to add extensions or add-ons to your browser.
  • Official Tampermonkey website.