User agent parser
Read the browser, engine, operating system and device type from a user agent string.
Runs in your browser. Your input is not uploaded.
What it does
Browsers send a User-Agent header describing themselves. Because every browser has copied parts of others over the years, the string is hard to read by eye: Chrome claims to be Mozilla, Safari and KHTML.
The parser uses the bowser library to pull out the browser, version, rendering engine, operating system and device type. It starts with your own browser’s string.
How to use it
- Read your own user agent, or paste one from a log.
- Check the parsed fields.
Things to watch for
- User agents are easy to fake and are being reduced by browsers. Use feature detection, not the user agent, to decide what code to run.
- Chrome’s reduced user agent reports a fixed OS version, such as Windows NT 10.0 on Windows 11.
Questions
- What is my user agent?
- It is shown at the top of the tool, read from
navigator.userAgent. - Why does every user agent start with Mozilla/5.0?
- Historical compatibility. Servers once checked for “Mozilla” to send modern pages, so every browser added it.
- Can I detect bots?
- Well-behaved crawlers name themselves, such as Googlebot. Others do not, so a user agent is not proof.
- What are client hints?
- Newer
Sec-CH-UAheaders that send browser details separately and only when asked. They are replacing parts of the user agent.