# UserScript Pro: Custom JS & CSS

> A premium, minimalist developer tool to inject custom JavaScript and CSS into any website. Features a boutique workspace with Ace Editor, real-time injection, and advanced URL matching.

Canonical page: [https://chrome-stats.com/d/userscript-pro-custom-js-css?hl=ko](https://chrome-stats.com/d/userscript-pro-custom-js-css?hl=ko)

## Overview

- **ID:** `userscript-pro-custom-js-css`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** aitchess
- **Category:** web-development,appearance
- **Daily users:** 3
- **Weekly downloads:** 3
- **Rating:** 5.00 / 5 (1 ratings)
- **Version:** 1.2.2
- **Last updated:** 2026-03-20
- **First published:** 2026-01-28
- **Size:** 4.01 MB
- **Data as of:** 2026-09-05
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/userscript-pro-custom-js-css/)

## Description

UserScript Pro is a high-end, boutique developer extension designed for precise web customization. It provides a clean, monochromatic environment for managing and injecting custom scripts and styles into web pages.

Key Features: - Advanced Code Editor: Powered by Ace Editor with syntax highlighting for JS and CSS. - Real-time Injection: Instantly run your code on the active tab without refreshing. - Smart Pattern Matching: Support for Glob patterns and Regex to target specific URLs. - Pro Workspace: Ultra-minimalist, distraction-free UI inspired by premium developer tools. - Secure & Performance-focused: Built with Manifest V3 and safe DOM APIs.

## Rankings

- #52,492 — Overall
- #159 — script
- #232 — custom feed
- #234 — custom font

## Permissions and access

### Permissions

- `storage`
- `scripting`
- `tabs`
- `activeTab`

### Host permissions

- `<all_urls>`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** High risk impact
- **Risk likelihood:** Moderate risk likelihood

### Analysis details

- Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

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Source: [Chrome-Stats](https://chrome-stats.com/d/userscript-pro-custom-js-css?hl=ko)