Change User Agent Permanently in Firefox [How to]

This can be done right from the about:config page

3 min. read

Updated onJuly 16, 2024

updated onJuly 16, 2024

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Sometimes it’s necessary to change your user agent in Firefox, especially if you’re developing a new web app, so in today’s guide, we’ll show you how to do that.

How do I change my user agent in Firefox?

1. Use about:config page

Keep in mind that you need to find the exact user agent string on your own for the desired browser version.

2. Use extensions

Where is the Firefox user agent?

Firefox doesn’t have a setting that lets you change the user agent. Instead, you need to use the about:config page or extensions to do so.

Is it illegal to change user agent?

No, it’s not illegal to change the user again. Many developers use this option when optimizing their websites. Speaking of which, if you’re a developer, you might want todownload Firefox Developer Editionand give it a try.

How do I reset my user agent?

If you’re using extensions to change the user agent, disable or uninstall them.

As you can see, it’s pretty simple to change user agent on Firefox, and while it’s possible to do that without extensions, extensions tend to be simpler to use and might be a better option for less experienced users.

Keep in mind that issues with user agents can occur, and we wrote aboutReddit user agent errorin one of our older guides.

To learn more about Firefox, we have great guides onFirefox profile locationas well as guide that shows you how todisable hardware acceleration in Firefox, so don’t miss them.

Change User Agent Permanently in Firefox [How to]#

How do I change my user agent in Firefox?#

1. Use about:config page#

2. Use extensions#

Where is the Firefox user agent?#

Is it illegal to change user agent?#

How do I reset my user agent?#