What this tool does
When you open the page it reads your browser’s user agent string and shows it along with a short summary: browser name, version, operating system and device type. You can also paste a different user agent string, for example from a server log, to see how it would be read.
It runs in your browser, so the string is not sent to this site’s server.
What is a user agent?
It is a line of text your browser sends with every request, saying what it is. A typical one looks like Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 ... Chrome/126.0 Safari/537.36. The “Mozilla/5.0” start and the mention of several other browsers are historical. Browsers imitated each other to avoid being blocked, so almost every string names more browsers than the one you are using.
How this tool reads it
The tool checks the string against a short list of patterns. It looks for Edge before Chrome, and Chrome before Safari, because those browsers include each other’s names. It recognises Windows, macOS, iOS, iPadOS, Android, Linux and Chrome OS, and calls a device “Mobile”, “Tablet” or “Desktop” from the OS match.
That is a simple approach. It doesn’t recognise every browser, such as Samsung Internet or Brave (which hides itself as Chrome), and it doesn’t identify bots or specific device models. Unknown values show as “Unknown”.
Why it matters
- Debugging a layout bug that only happens on one browser
- Copying your exact string into a bug report
- Checking what a crawler’s user agent in your log file means
- Testing how a server responds to a different user agent
Many modern browsers are reducing the detail in the user agent string, so don’t rely on it for feature detection. Test for the feature itself.
Can I change my user agent with this tool?
No. It only shows and parses a string. To send a different user agent use your browser’s developer tools or a command-line client.
Why does my Chrome string mention Safari and Mozilla?
Historical compatibility. Browsers have copied each other’s names for years so servers wouldn’t block them.
Does it identify search engine bots?
No. It only recognises common desktop and mobile browsers and operating systems.
Is my user agent sent to the site?
This tool reads it in your browser. Your browser still sends it to every website you visit as part of normal requests.
Can I paste a user agent from a server log?
Yes. Paste any string into the box and the tool shows how it reads the browser, version, operating system and device type.