A support ticket arrives with a two-hundred-character User-Agent string full of historical compatibility tokens, and you need to know which browser and platform to reproduce on.
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User Agent Parser
User-Agent string
Free · API · MCPToolYour platform
Use User Agent Parser three ways
The free User Agent Parser on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse User Agent Parser here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is User Agent Parser?
A support ticket arrives with a two-hundred-character User-Agent string full of historical compatibility tokens, and you need to know which browser and platform to reproduce on. This user agent parser extracts the browser name and version, the operating system and its version, and whether the client looks like a mobile or desktop device.
Detection is heuristic and deliberately narrow: Chrome, Edge, Firefox, and Safari for browsers, and Windows, macOS, Android, iOS, and Linux for platforms, with everything else reported as unknown rather than guessed. That is honest but limited — User-Agent strings are trivially spoofed, in-app webviews frequently masquerade as Safari or Chrome, and modern browsers are freezing the string in favour of Client Hints headers this tool never sees. Use it for triage, not for analytics truth, licensing, or bot scoring. When the log line also contains an address you need to classify, IP Address Tools handles that half.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/user-agent-parser and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about User Agent Parser?
How accurate is the detection?
Good enough to reproduce a bug, not good enough to bill on. Strings are spoofable and webviews often impersonate mainstream browsers.
Does it read Client Hints?
No. It parses the single string you paste. Client Hints arrive as separate request headers that this tool never receives.
Which browsers and platforms are recognised?
Chrome, Edge, Firefox, and Safari, on Windows, macOS, Android, iOS, and Linux. Anything else returns unknown instead of a guess.
What are the key features of User Agent Parser?
Browser, OS, and device in one call
Names and versions extracted into structured fields you can log or compare.
Unknown instead of wrong
Unrecognised clients are reported as unknown rather than forced into the nearest match.
Purely local parse
No lookup service or network call, so it is fast and costs a single credit.
How do you use User Agent Parser?
Copy the UA string
From an access log, a request header dump, or a support ticket.
Parse it
Read the browser, platform, and device classification.
Reproduce the issue
Match the browser and platform in a real device or emulator before debugging.
Why the User-Agent string is unreliable
The string is a historical accident. Nearly every browser claims to be Mozilla, Chrome-based browsers also claim Safari and WebKit, and Edge appends its own token at the end. Parsing therefore depends on checking the more specific tokens before the generic ones, which is why order-of-detection bugs are so common in hand-rolled parsers.
On top of that, the value is client-controlled. Anyone can set it to anything, privacy tooling randomises it, corporate proxies rewrite it, and mobile in-app browsers report their host application inconsistently. Treat every parsed field as a claim by the client, not a fact about it.
Client Hints and the road ahead
Browsers are reducing the detail in the User-Agent string and moving specifics into Client Hints headers such as Sec-CH-UA and Sec-CH-UA-Platform, which a server requests explicitly. That means UA-based version detection will keep getting less precise over time, and any logic depending on an exact version number should migrate.
The durable answer is feature detection rather than browser detection in the client, with UA parsing kept for what it is genuinely good at: grouping support tickets and spotting an obviously odd client in a log. Pair it with IP Address Tools when triaging traffic that looks automated.
Which HTTP / auth helper tools sit in this cluster?
Where do you browse more developer tools tools?
- Developer Tools tools
Browse the full Developer Tools category on ToolYour.
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Build UTM links, check ads copy limits, QA email subjects, and calculate ROAS/CPC/CTR — free in the browser; R
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