User Agent Switcher
User-Agent Switcher and Manager lets users modify the browser User-Agent string that websites use to select delivered content.
About User Agent Switcher
User Agent Switcher and Manager is a browser extension that changes the User-Agent string your browser sends to websites. Web servers use this string to decide what content, styling, or JavaScript to deliver, so altering it can make sites treat your browser as a different device or operating system. The extension also adjusts related Client Hints headers and the navigator.userAgentData object to match the chosen string.
With it, you can pick a predefined User-Agent string filtered by browser or operating system, edit it, or create a custom one. You can randomize strings to enhance anonymity and apply overrides per tab or per hostname. When the default User-Agent is in use, the extension deactivates itself and does not use resources. It only affects HTTP and HTTPS pages; locally loaded FILE pages bypass the override.
It suits people who want to view mobile content on a desktop, test how pages behave under different browser identities, or reduce exposure of their actual browser identity.
Key features
- Spoofs or rewrites the User-Agent string sent with each request
- Create custom User-Agent strings or randomize them for anonymity
- Apply User-Agent overrides per tab or per hostname
- Adjusts Client Hints headers and navigator.userAgentData object
- Deactivates when default User-Agent is used, with no performance impact
- Filter predefined User-Agent strings by browser or operating system
Best for: People who want to view mobile content on desktop, test sites under different browser identities, or reduce exposure of their actual User-Agent.
Good for
- Includes Client Hints and userAgentData support for modern browser identification
- Supports per-tab and per-hostname overrides
- No performance impact when inactive
- Custom and randomized strings are supported
Watch out for
- Only alters the User-Agent for HTTP and HTTPS pages; local FILE pages are not affected
User Agent Switcher at a glance
- Category
- Software & Utilities › Browser Extensions
- Type
- Website
- Pricing
- Not confirmed. Check the site
- Platforms
- Web
- Open source
- Not stated
- Language
- English
- Last checked
- Oct 5, 2026 · Online when checked
- Listed
- Oct 5, 2026
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User Agent Switcher FAQ
What does User Agent Switcher and Manager do?
It overrides the navigator.userAgent string and modifies the User-Agent header sent with each request. It also adjusts Client Hints headers and the navigator.userAgentData object to match the chosen string.
How do I set a custom User-Agent string?
Click the toolbar button to open the popup, select a predefined string or paste your own into the text box, then press the Apply button. You can filter strings by browser type or operating system.
Does the extension affect performance when disabled?
No. When you press the Reset button in the toolbar popup, the extension is inactive, does not manipulate network traffic, and unregisters its JavaScript override function.
Does it work on local HTML files?
It only alters the User-Agent for HTTP and HTTPS schemes. Locally loaded pages with the FILE scheme bypass the extension and display your actual User-Agent string.
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