# JShelter

> JShelter controls the APIs provided by the browser. The goal is to improve the privacy and security of the user running the extension.

Canonical page: [https://chrome-stats.com/d/javascript-restrictor](https://chrome-stats.com/d/javascript-restrictor)

## Overview

- **ID:** `javascript-restrictor`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Libor Polčák
- **Category:** web-development,privacy-security
- **Daily users:** 383
- **Weekly downloads:** 17
- **Rating:** 4.51 / 5 (49 ratings)
- **Version:** 0.24.4
- **Last updated:** 2026-07-27
- **First published:** 2019-02-27
- **Size:** 498 KB
- **Data as of:** 2026-09-11
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/javascript-restrictor/)
- **Website:** [https://jshelter.org/](https://jshelter.org/)

## Description

**JShelter** is a powerful browser extension designed to enhance your online privacy and security by controlling the APIs accessible via JavaScript. Web pages often use JavaScript to gather detailed information about your browser and device, enabling tracking and fingerprinting. JShelter acts as a firewall for your browser's APIs, allowing you to restrict or modify the data that websites can access.

With JShelter, you can choose to block or limit specific actions, such as reducing geolocation precision or denying access to certain hardware data, effectively shielding you from malicious tracking and attacks on your browser or device. This extension empowers users to regain control over their browsing experience by customizing privacy settings per website. For detailed information, see their [FAQ](https://jshelter.org/faq/), [blog](https://jshelter.org/blog/), and [threat model](https://jshelter.org/threatmodel/).

## Rankings

- #5,864 — Overall
- #44 — goal
- #140 — improve
- #178 — provide
- #213 — javascript

## Permissions and access

### Permissions

- `storage`
- `tabs`
- `webRequest`
- `webRequestBlocking`
- `webNavigation`
- `dns`
- `<all_urls>`
- `notifications`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** Very 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).

## Review summary

### Pros

- Comprehensive fingerprint protection
- Works against Creepjs fingerprinter
- Provides extra protection when JavaScript is enabled
- First tool to effectively eliminate cross-site tracking

### Cons

- High CPU and memory usage
- Causes issues with many websites, especially those using CAPTCHA
- Some sites are blocked or display messages like 'This Browser Is Out of Date'
- Notifications can be overwhelming and become noise

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Source: [Chrome-Stats](https://chrome-stats.com/d/javascript-restrictor)