Web browsers identify themselves to web pages with a user agent. The user agent string includes information about your device. Web developers will sometimes create different versions of a page to be delivered for different user agents.

Compatibility issues

If a web page is designed to check for a user agent, it may include a fallback page. Depending on the site, this is usually a simple layout for mobile phones or an error page advising you to upgrade your browser. This can create a problem if the web developer only targeted the most common browsers and you are using an uncommon browser like K-Meleon. If you are receiving "upgrade your browser messages" or getting the mobile version of a web page, this is likely the issue.

To fix user agent compatibility issues you can run K-Meleon in Firefox Compatability mode. This does not change anything within K-Meleon. It will simply identify the browser as a version of Mozilla Firefox (a common web browser that K-Meleon shares code with), and web pages will then deliver the Firefox version of that page. Firefox compatibility is often turned on by default in K-Meleon. If you need to turn it back on go to Tools > Firefox compatibility mode and click to activate.

View current User-Agent

To view your current user agent go to Help > About K-Meleon and it will be listed near the top of the about window.

If you need to frequently check your user agent due to a poorly designed website, you can add a button to your toolbar. To add a user agent button to your privacy toolbar edit the configuration files in a text editor.

Other User Agents

It is possible to change your user agent to any string of text. If Firefox compatibility mode is not working for a certain website you can change your user agent to another version of Firefox or even unrelated web browser identities. To use a specific User-Agent for a website:

1. Type about:config into the address bar.
2. You will likely see a warning explaining that changing these settings will affect your browser.
3. Search for the website that is causing you problems. If you don't see a custom user agent already in use for it, continue to the next step.
4. Right click and choose new string.
5. For preference name type general.useragent.override.<website>.com and for the value copy and paste the user agent you want to use.

You can also temporarily switch to a custom user agent for all pages in all tabs with the Useragent 2018 extension. To temporarily switch to a custom user agent:

1. Download the Useragent 2018 extension in this thread: http://kmeleonbrowser.org/forum/read.php?9,143898,152304
2. Save the K-Meleon macro module (.kmm) file to your K-Meleon/macros/ folder or Profiles/your.profile/macros/ folder.
3. Restart K-Meleon.
4. Go to Tools > User Agents 2018 and you will see options to create and use custom user agents.