My user scripts to add functionality to various sites around the web (that were too small for me to bother turning into a full-fledged Chrome extension).

• Amazon Prime Gaming Highlighter (Install)
• Bypass Right-Click Jacking (While Key Held) (Install)
• ChatGPT Web App Script Update Notifier (Install)
• Copy GitHub Repo Summary (Install)
• Freshdesk Make 'Redactor Editor' Resizeable (Install)
• GitHub Gist - CodeMirror Resizer (Install)
• GitHub Notifications - Arrow key navigation (Install)
• Google developer sites - Ensure ?authuser= by default (Install)
• Nourishd Meal Highlighter (Install)
• YouTube Speed Override (Install)

Personally I used Violentmonkey in Chrome:

• Violentmonkey (Install, Chrome, Source)
  • Creating a userscript
  • GM_* APIs

But since Violentmonkey haven't updated from MV2 to MV3 (at least as of 2025-08-24):

• Issue #1934: [Feature] Manifest V3 for Chrome
• Issue #2284: New Chrome version doesn't support it
• Commit 196814a

  • WARNING:

    This extension is no longer supported on Chrome due to its Manifest V2 architecture. While a Manifest V3 rewrite might be considered in the future, it is not planned for the foreseeable future due to the considerable effort involved and the potential for losing existing features.

    As an alternative, consider using Brave browser which is also open source, where you can install it from the Chrome Web Store.

I was forced to move back to Tampermonkey (which is not open source):

• Tampermonkey (Chrome)

That said, TamperMonkey has support for some more experimental features/API's that Violentmonley doesn't/won't support (eg. GM_webRequest(rules, listener), GM_cookie.*, etc; Ref: violentmonkey#583, tampermonkey#397)

Another open source alternative (that I haven't deeply explored / tried) is ScriptCat, which is GPLv3 and updated for MV3:

• https://github.com/scriptscat/scriptcat
  • https://github.com/scriptscat/scriptcat/blob/main/README_EN.md
  • Install: Chrome

And finally, if you have different preferences, the following more comprehensive (but older) guide was extracted from the bvolpato/awesome-userscripts README (though this extract isn't updated with info on MV2 vs MV3 support):

To use user scripts you need to first install a user script manager. Here are managers for various browsers:

• Greasemonkey - Firefox
  • Supports GM 4 userscripts.
• Greasemonkey for Pale Moon - Pale Moon
  • Supports GM 3 userscripts.
• Firemonkey - Firefox
  • Supports GM 4 userscripts and some GM 3 userscripts.
• Tampermonkey - Chrome, Microsoft Edge, Safari, Opera, Firefox (also with support for mobile Dolphin Browser and UC Browser)
  • Supports both GM 3 and GM 4 userscripts.
• USI - Firefox
  • Supports some GM 3 userscripts.
• Violentmonkey - Chrome, Firefox, Maxthon, Opera
  • Supports both GM 3 and GM 4 userscripts.

The most popular userscript managers are Greasemonkey, Tampermonkey, and Violentmonkey.

Chrome DevTools allows you to save small snippets of JS code that can be easily run on pages using Command + P, typing a !, then selecting the snippet you want to run:

• https://developer.chrome.com/docs/devtools/javascript/snippets/

While I won't list them all here individually, you can find my devtools userscripts (or those I've collected from others), in:

• ./devtools-snippets/

• https://www.devalias.net/ (source)
  • My Blog
• https://github.com/0xdevalias (profile source)
  • My GitHub Profile
  • My Repos
    • chrome-* (Chrome Extension) repos
    • poc-* (Proof of Concept) repos
• https://github.com/0xdevalias/dotfiles

  • devalias does dotfiles

• https://github.com/0xdevalias/chrome-NewWindowWithTabsToRight (Announcement Blog, Chrome Webstore)

  • Create a new window from the tabs to the right of the currently selected tab.

• https://github.com/0xdevalias/userscripts (this repo!)

  • My user scripts to add functionality to various sites around the web (that were too small for me to bother turning into a full-fledged Chrome extension)

• https://github.com/0xdevalias/awesome-gmail-filters

  • Awesome list of Gmail filters and related resources

• My Homebrew Contributions
  • Homebrew/homebrew-core PRs
  • Homebrew/homebrew-cask PRs
  • Homebrew/homebrew-cask-versions PRs
  • etc
• Probably a lot more around the net that I haven't thought to link to here.. hope you find something cool/useful out there!

A non-exhaustive list of userscripts created by others/from other repos/etc:

• https://github.com/bvolpato/awesome-userscripts

  • A curated list of Awesome Userscripts

• https://github.com/Mottie/GitHub-userscripts

  • Userscripts to add functionality to GitHub

• https://bitbucket.org/mottie/bitbucket-userscripts

  • Userscripts to add functionality to Bitbucket

• https://gitlab.com/Mottie/GitLab-userscripts

  • Userscripts to add functionality to GitLab

• https://github.com/Mottie/Misc-userscripts

  • Userscripts to add functionality to miscellaneous sites

• https://github.com/jerone/UserScripts

  • This repo contains a few of my UserScripts that I've build since 2007.

A non-exhaustive list of JS devtools snippets created by others/from other repos/etc:

• https://github.com/bgrins/devtools-snippets

  • A collection of helpful snippets to use inside of browser devtools

  • https://bgrins.github.io/devtools-snippets/

Pretty much my go-to Chrome extension for making GitHub way more usable:

• https://github.com/refined-github/refined-github (Chrome, Firefox, Safari)

  • Browser extension that simplifies the GitHub interface and adds useful features

Also a super useful Chrome extension for GitHub Notifications:

• https://github.com/tanmayrajani/notifications-preview-github (Chrome, Firefox)

  • Browser Extension: preview GitHub notifications with same page pop-overs