User-Agent Switcher and Manager

By: Ray

Spoof websites trying to gather information about your web navigation—like your browser type and operating system—to deliver distinct content you may not want.

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Features & Capabilities

User-Agent Switcher and Manager lets you spoof your browser "user-agent" string to appear as a different browser, OS, or device. Use it to load mobile site versions for speed, test site behavior across browsers, or reduce tracking and content tailoring by masking identifying details. Quick toolbar controls make switching immediate and simple.

Features include per-site and per-window user-agent settings, an option to randomize user-agent strings, and a two-factor mimic technique for reliable spoofing. The extension supports modern identification methods (Client Hints and navigator.userAgentData), lets you exclude domains, and uses no resources when not actively spoofing. Ideal for developers, privacy-conscious users, and anyone who wants consistent, customizable browsing behavior.

User Growth & Download Statistics

Add-on Privacy & Security Developer Tools

By:

Ray

Daily users:

85,908 298

Rating:

4.06

(782)

Version:

0.6.7 Last updated: 2026-04-24

Version code:

6229496

Creation date:

2017-09-13

Risk:

Permissions:

storage
contextMenus
scripting
declarativeNetRequestWithHostAccess
webRequest

Host permissions:

<all_urls>

Size:

866.08KB

URLs:

Website

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-16

Compare stats and ranking:

Ranking

# 239 ▼ 1

Other rankings

#7 in Web Development

#13 in Privacy & Security

#1 in agenda keyword 21

#1 in agent keyword 62

#1 in deliver keyword 6

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Other platforms

User-Agent Switcher and Manager (v0.6.7)

300,000 4.33

(271)

User-Agent Switcher and Manager (v0.6.7)

197,997 4.60

(29)

For Developers

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Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

Ray

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/user-agent-string-switcher/

Website:

https://webextension.org/listing/useragent-switcher.html

Permission Change History

2026-04-24: Version 0.6.6 → 0.6.7

Add Permissions: webRequest

2025-05-27: Version 0.5.0 → 0.6.5.1

Add Host permissions: <all_urls>

Add Permissions: scripting declarativeNetRequestWithHostAccess

Remove Permissions: <all_urls> webNavigation webRequest webRequestBlocking

Remove Optional permissions: cookies

User Reviews

User reviews for the Firefox add-on show a split experience. A few users found it very useful and rated it among the best UA switchers, especially when it worked and could outperform alternatives on some sites. However, the majority report reliability problems: the extension frequently stops functioning across updates and Firefox versions, and it can break YouTube playback and Google searches, sometimes prompting captchas. Compatibility issues are common, including broken whitelist/containers features and failures on newer Firefox forks. Overall, while it can be helpful in narrow use cases, its reliability and ongoing support are major concerns.

Pros

When it worked, it was very useful and praised as one of the best UA switchers.
It performed well compared to other UA switchers and could fool some sites.
It still had value in scenarios that don't require up-to-date user agents.

Cons

Frequently stops working or becomes non-functional across updates and Firefox versions.
Breaks YouTube playback after a short time, causing the player to stop or crash.
Disrupts Google search and can trigger captchas.
Compatibility issues: broken whitelist/containers features, failures on newer Firefox forks, and removal of per-container UA assignment.
Poor reliability on Android and in general.

Recent reviews

For a long time this was my go-to add-on for user agent removal and randomisation, but it stopped working at some point. I run it in custom mode, but it simply always sends my real User-Agent.

by An*****, 2026-06-03

Hi, thanks for the add-on. It was a bit difficult at first to figure out how it works, but after I discovered that all the buttons have tooltips, it got much easier. I have an enhancement suggestion: perhaps it would be more convenient if the filter in the popup window would not simply grey out items that don't match it, but hide (collapse) them, so that only what the user searches for is displayed.

by mk*****, 2026-06-03

I fully agree with the review by Cr: "This extension is unbelievably user-hostile. ..."

by ha*****, 2026-05-28

View all user reviews ›

Is User-Agent Switcher and Manager Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

User-Agent Switcher and Manager requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
High ****** *** ********* ** ******* *** ******* ******* ** ****** *** *** ******** ******

Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

User-Agent Switcher and Manager has earned a good reputation and can be trusted.

Risk likelihood analysis details

Medium This extension was updated in the past 3 months. New updates may not be stable or safe.
Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
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Good **** ********* ** ****** ** ********
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