Custom JavaScript for Websites icon

Custom JavaScript for Websites

by QP

v1.04 Updated Mar 9, 2026 1.89MiB
CWS
3K
Users
★ 5.00
3 reviews
#13239
of 207.6K
accessibility
#683 of 6.4K
⚠️Very few reviews for its user base Recently updated

Description

Custom JS Injector allows you to run your own JavaScript code on any website. You can write, inject, and store custom scripts per domain — all from a clean, intuitive popup interface. ✨ **Features**: - 💻 Inject JavaScript into any website via popup UI - 💾 Automatically saves your script per domain - 🔁 Auto-inject on page reload — no need to click again - 🔒 Scripts are stored locally (no remote sync or upload) - 🧠 No external dependencies, no bloat — just pure custom JS! 🚀 **Use Cases**: - Debug page behavior or experiment with ideas - Clean up UI or hide elements - Extract data from web apps or dashboards - Apply personal UI/UX fixes on internal tools 📝 **Important Notice – Website Restrictions**: This extension **does not work** on some websites that actively block JavaScript injection through browser-level security mechanisms like **Content Security Policy (CSP)**. These websites include, but are not limited to: - `google.com` - `facebook.com` - `twitter.com` - `chrome.google.com` Due to these restrictions, the extension’s inject feature will **not function** on those sites. This is expected behavior, and not a bug or issue with the extension. To test or use this extension, please try it on other websites that do not have strict CSP rules — such as: - `example.com` - `wikipedia.org` - internal tools or custom dashboards 📌 **Privacy**: This extension only uses local storage. **No data is shared, synced, or uploaded remotely.**
Custom JavaScript for Websites screenshot 1Custom JavaScript for Websites screenshot 2

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Permissions (3)

Permissions

scripting Can inject scripts into web pages storage Can store data locally in your browser tabs Can see your open tabs and their URLs

Details

Version 1.04
Updated Mar 9, 2026
Size 1.89MiB
First Seen Mar 30, 2026