# Custom JS & CSS for Safari — Run JS, CSS & userscripts

> Safari extension to run custom JavaScript, CSS, and userscripts on websites. (iPhone/iPad app by Alfredo Grassau.)

- Source: https://appshunter.io/ios/app/custom-js-and-css-for-safari/id6776793703 (this page in markdown: same URL + `.md`)
- Developer: [Alfredo Grassau](https://appshunter.io/developer/1564157928)
- Category: Developer Tools, Utilities
- Price: $2.99
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 15.0 · 10 MB
- Languages: Russian, American English, European Spanish, Italian, Korean, German (Germany), Polish, Brazilian Portuguese, Chinese (Simplified, China), French (France) and 1 more
- Released: 2026-06-08
- Data updated: 2026-09-07
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/custom-js-and-css-for-safari/id6776793703/reviews.md

## What is Custom JS & CSS for Safari?

Custom JS & CSS for Safari is a powerful Safari Extension that lets you personalize the web with your own JavaScript, CSS, and userscripts. Create site-specific enhancements, visual tweaks, automations, and custom browsing tools directly in Safari.

Features:

· Add Custom JavaScript: Run your own JavaScript on any website directly in Safari.

· Add Custom CSS: Style websites with your own CSS rules and visual tweaks.

· Site-Specific Rules: Apply scripts and styles to a single domain, exact URL, all websites, or custom match patterns.

· Run Scripts Manually or Automatically: Choose whether each script runs on its own or only when you activate it.

· Userscript Manager: Import, organize, and run userscripts from popular userscript libraries like Greasy Fork.

· Popup and Custom Editor: Add or edit scripts directly from the extension popup or in a dedicated custom editor.

· iCloud Sync: Keep your scripts and styles synced across iPhone, iPad, and Mac using iCloud.

· Privacy-first design: No data collection, tracking, or logging, your browsing stays completely private.

· Multilingual support: Use the extension in multiple languages for a globally friendly experience.

· Clean, user-friendly UI: Enjoy a streamlined design that integrates smoothly into your workflow.

· Seamless Safari integration: Built to work flawlessly across Safari on macOS, iOS, and iPadOS.

## Key features

- Add custom JavaScript
- Add custom CSS
- Site-specific rules
- Userscript manager
- iCloud sync
- Privacy-first design

## Chart rankings

- #35 in Top Paid · Developer Tools (US App Store)


## Frequently asked questions about Custom JS & CSS for Safari

### What is Custom JS & CSS for Safari?

Custom JS & CSS for Safari is a Safari Extension that allows you to run your own JavaScript, CSS, and userscripts on any website directly within Safari. It helps you personalize the web with custom enhancements and automations.

### How much does Custom JS & CSS for Safari cost?

Custom JS & CSS for Safari is a paid application, priced at $2.99. There are no in-app purchases or subscriptions required after the initial purchase.

### Does Custom JS & CSS for Safari have ads?

No, Custom JS & CSS for Safari is ad-free. The developer prioritizes a clean and private browsing experience without advertisements.

### What devices is Custom JS & CSS for Safari compatible with?

Custom JS & CSS for Safari is designed to work seamlessly across Apple devices, including Mac, iPhone, iPad, and iPod. It utilizes iCloud Sync to keep your scripts and styles consistent across these platforms.

### How often is Custom JS & CSS for Safari updated?

The app was last updated on June 9, 2026, with version 1.0.3. While specific update frequency isn't detailed, this indicates ongoing development and support.

### Can I import userscripts from other libraries with Custom JS & CSS for Safari?

Yes, Custom JS & CSS for Safari includes a Userscript Manager that allows you to import, organize, and run userscripts from popular libraries like Greasy Fork.

### Is my browsing data collected by Custom JS & CSS for Safari?

No, Custom JS & CSS for Safari features a privacy-first design. It does not collect, track, or log any of your data, ensuring your browsing remains completely private.

### What is the age rating for Custom JS & CSS for Safari?

Custom JS & CSS for Safari has an age rating of 4+. This indicates it is suitable for a wide range of users, including younger individuals, due to its non-sensitive content.

## Version history (last 3 releases)

### 1.0.6 — 2026-08-07

Bug fixes and performance improvements.

### 1.0.5 — 2026-07-08

Bug fixes and performance improvements.

### 1.0.3 — 2026-06-09

No release notes.

## More apps by Alfredo Grassau

- [BlueMount - Money manager](https://appshunter.io/ios/app/bluemount-money-manager/id1564157925)
- [ShadeView Dark Mode for Safari](https://appshunter.io/ios/app/shadeview-dark-mode-for-safari/id6458188395)
- [What Font for Safari](https://appshunter.io/ios/app/what-font-for-safari/id6468666357)
- [Color Sense for Safari](https://appshunter.io/ios/app/color-sense-for-safari/id6468950602)
- [CSS Inspector for Safari](https://appshunter.io/ios/app/css-inspector-for-safari/id6469319815)
- [SVG Picker for Safari](https://appshunter.io/ios/app/svg-picker-for-safari/id6470751890)

All apps by Alfredo Grassau: https://appshunter.io/developer/1564157928

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*