# User-Agent Auto Spoofer > Assign custom, site-specific User-Agent overrides (Desktop, Mobile, or Web Crawler). Canonical page: [https://chrome-stats.com/d/user-agent-auto-spoofer](https://chrome-stats.com/d/user-agent-auto-spoofer) ## Overview - **ID:** `user-agent-auto-spoofer` - **Platform:** Firefox - **Type:** Firefox add-on - **Status:** Available - **Publisher:** Chris Judevine - **Category:** web-development,privacy-security - **Daily users:** 8 - **Weekly downloads:** 1 - **Version:** 1.0.1 - **Last updated:** 2026-07-15 - **First published:** 2026-07-09 - **Size:** 16 KB - **Data as of:** 2026-09-06 - **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/user-agent-auto-spoofer/) - **Website:** [https://chris-judevine.blogspot.com/2026/07/firefox-user-agent-automatic-switcher.html](https://chris-judevine.blogspot.com/2026/07/firefox-user-agent-automatic-switcher.html) ## Description Per-Site User-Agent Switcher & Spoofer puts you in complete control over how websites perceive your browser and device environment. Instead of forcing a blanket, global identity change that breaks half the web, this extension uses a granular rules system to inject targeted headers and window overrides on a strict per-site basis. Simply add a domain, assign its target profile, and browse seamlessly. 8 Built-In Profiles Supported: Desktop Browsers: Firefox Desktop, Google Chrome, Microsoft Edge, Safari Desktop Mobile Browsers: Android Firefox, Android Chrome, Safari Mobile (iPhone) Web Crawlers: Googlebot Key Features: Set a unique profile for each site or keep it blank to retain your natural browser properties. Deep Client Spoofing: Seamlessly updates both network request headers (User-Agent) and front-end execution characteristics (navigator.userAgent and navigator.platform). Privacy-First Design: Fully open-source, uses minimal WebExtension permissions, operates entirely locally on your machine, and never tracks your browsing patterns. Developer Note on Anti-Fingerprinting: If you are using this to avoid installing a sites app on Android devices, we highly recommend opening advanced settings and manually toggling privacy.resistFingerprinting Sites such as reddit.com will detect you are using mobile without this enabled. The extension includes a single-click convenience shortcut to copy the configuration URL to your clipboard. ## Rankings - #36,900 — Overall - #166 — spoon ## Permissions and access ### Permissions - `storage` - `webRequest` - `webRequestBlocking` - `privacy` ### Host permissions - `http://*/*` - `https://*/*` ### Content script matches - `*` ## Safety - **Risk impact:** High risk impact - **Risk likelihood:** High risk likelihood ### Analysis details - Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site. - 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). ## Similar extensions and apps - [User Agent Switcher – Change & Manage](https://chrome-stats.com/d/user-agent-switcher-change) — 3 users - [Agent Spoofer](https://chrome-stats.com/d/agent-spoofer) — 55 users - [User-Agent Switcher and Manager](https://chrome-stats.com/d/user-agent-string-switcher) — 85,389 users, 4.08 / 5 - [Browser Spoofer](https://chrome-stats.com/d/browser-spoofer) - [User-Agent Switcher PRO](https://chrome-stats.com/d/user-agent-switcher-pro) — 48 users, 4.00 / 5 - [User Agent Spoofer](https://chrome-stats.com/d/advanced-user-agent-spoofer) — 23 users, 1.00 / 5 - [User-Agent Switch PC b8q](https://chrome-stats.com/d/smart-ua-manager) — 95 users - [User-Agent Switcher and Simulator](https://chrome-stats.com/d/useragent-simulator-switcher) — 234 users, 4.64 / 5 - [Advanced User-Agent](https://chrome-stats.com/d/advanced-user-agent) — 5 users - [Chrome UA Spoofer](https://chrome-stats.com/d/chrome-ua-spoofer) — 2 users - [User Agent Platform Spoofer](https://chrome-stats.com/d/user-agent-platform-spoofer) — 184 users, 4.80 / 5 - [Chrome Spoofer](https://chrome-stats.com/d/chrome-spoofer) — 11 users --- Source: [Chrome-Stats](https://chrome-stats.com/d/user-agent-auto-spoofer)