Witchcraft: JS/CSS injector icon

Witchcraft: JS/CSS injector

by Lucio Paiva · luciopaiva.com · Developer Tools
Established publisherManifest V3 Free
View in Chrome Web Store Data as of 15 Oct 2026

Witchcraft loads custom Javascript and CSS directly from a folder in your file system. Think GreaseMonkey for developers.

Users
1,000
+11 in 30 days
Rating
4.9 / 5
unchanged in 30 days
Ratings
10
0 in 30 days
Store rank
#26K
#21K among extensions
Version
3.2.0
updated 15 Sep 2025

Users

monthly, 3 years
3006501,000Aug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 1,000 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 years
3711Aug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 10 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Witchcraft: JS/CSS injector

Think Greasemonkey for developers. Witchcraft is a Google Chrome extension for loading custom Javascript and CSS directly from a folder in your file system, injecting them into pages that match their files names. It works by matching every page domain against script file names available in the scripts folder. For instance, if one navigates to `https://www.google.com`, Witchcraft will try to load and run `google.com.js` and `google.com.css`. Witchcraft also tries all domain levels. For instance, if one accesses `https://gist.github.com`, it will try to load, in this order: `com.js`, `github.com.js` and `gist.github.com.js`... and the same for CSS. All domain levels for which a script is found will be loaded, not just the first one. Whenever you edit or create new scripts, there's no need to reload anything other than the page where the scripts are supposed to run. This is what makes Witchcraft special and different than other popular scripting tools, like Greasemonkey or Tampermonkey. Since Witchcraft runs as a Chrome extension, it is also cross-platform. It has been tested on Windows, MacOS and Linux. Features: * scripts are automatically updated after you edit them - no need to reload anything; * works on Windows, Mac and Linux; * handles both JS and CSS; * @include directive to load other JS/CSS files from inside your domain scripts. * custom server addresses (even remote ones) Please check the website if you want to learn more.

Growth

WindowUsersChangeRatingsRating
7 days+7+0.7%00.00
30 days+11+1.1%00.00
6 months0+0.0%−1+0.26
1 year0+0.0%0+0.30

Version history

4 versions recorded
3.2.015 Sep 2025
3.1.013 Sep 2025
3.0.010 Sep 2025
2.6.110 Mar 2020

Details

Category
Developer Tools
First seen
10 Mar 2020
Size
72 KB
Languages
en
Pricing
Free
Support
github.com
Extension ID
hokcepcfcicnhalinladgknhaljndhpc

Permissions and risk

Low riskimpact 2, likelihood 1
Permissions
webNavigationstorageactiveTabscriptinguserScripts
Site access
http://*/*https://*/*
Can read and change data on every website you visit.

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