Every browser sends a user agent string with each request, a compact but cryptic line that names the browser, its version, the operating system, and often the device. Reading one by eye is a chore, especially when the string carries legacy tokens from browsers that no longer exist. This parser takes any pasted user agent string and breaks it into browser, operating system, and device type, so a line from a log file or a bug report becomes immediately understandable. It recognises the major desktop and mobile browsers, the common operating systems, and mobile versus desktop form factors, and it says so plainly when a string does not match anything it knows. Support teams, developers, and analysts use exactly this kind of breakdown to reproduce browser-specific bugs and to understand who is really visiting a site.
Quick Answer: Paste a user agent string and instantly see its browser, operating system, and device type.
Free Online Tool
User Agent Parser
Turn a cryptic UA line into browser, OS, and device.
How to Use the User Agent Parser
- Copy a user agent string from a log, a bug report, or a browser.
- Paste it into the input box.
- Press Parse to break it into browser, OS, and device.
- Read the summary and check the version number shown.
- Paste another string to compare a second visitor or device.
Key Features
- Identifies Chrome, Edge, Firefox, Safari, and other major browsers.
- Detects Windows, macOS, Android, iOS, and Linux.
- Distinguishes mobile devices from desktop computers.
- Shows the browser version number when the string carries one.
- Explains unknown strings instead of guessing silently.
Best Practices and Tips
- Chrome’s string contains the word Safari for historical reasons, so a parser must check Chrome before Safari; this one does.
- Edge strings contain Edg, while old Internet Explorer strings contain MSIE or Trident, which helps date very old traffic.
- A user agent can be spoofed by anyone, so treat it as a hint about the client, never as proof of identity.
- Mobile detection from the string alone is a heuristic; the presence of Mobile, Android, iPhone, or iPad tokens is the usual signal.
- When debugging, compare the parsed result against what the user actually sees, because browser modes and extensions can alter the string.
Common Mistakes to Avoid
- Reading Safari in a Chrome string and concluding the visitor used Safari.
- Assuming the operating system version in the string is always precise; some browsers freeze or reduce it for privacy.
- Treating a parsed user agent as authentication; it is self-reported and trivially forged.
- Expecting every bot or rare browser to be recognised by name; unknown agents are reported as unknown, honestly.
Frequently Asked Questions
What is a user agent string?
It is a line of text a browser or client sends to identify itself, typically naming the browser, its version, the operating system, and the device class. Servers log it with every request, which is why log files are full of these long, parenthesis-heavy strings.
Why do Chrome strings mention Safari and Mozilla?
For compatibility history: early browsers identified as Mozilla, and later browsers added tokens from rivals so websites that sniffed for specific names would serve them full pages. Modern parsers therefore read the tokens in a careful order instead of trusting the first familiar name they see.
Can a user agent be faked?
Yes, trivially. Any client can send any string it likes, so user agents are useful for statistics, debugging, and rough compatibility decisions, but never for security decisions. Never grant access or trust based on a user agent alone.
What does this parser do with unknown strings?
It reports the browser or OS as unknown rather than inventing a match. That honesty matters in logs: an unknown string is often a bot, a script, or a new client, and labelling it as a familiar browser would hide exactly the information you need.
Does it show my own browser’s string?
Not automatically; this tool parses whatever you paste, so it works on log lines and reports from other people too. If you want your own details, use the Browser Info tool on this site, which reads your live browser directly.