--- title: "User-Agent Parser - Browser and Device Details" description: "Parse a User-Agent string into browser, engine, OS, device, CPU, and crawler details. Free, instant, and processed in your browser." url: https://candoya.com/tools/user-agent-parser/ locale: en type: browser-tool --- # User-Agent Parser Category: [Developer](https://candoya.com/tools/dev/) ## What is a User-Agent parser? A User-Agent parser turns an HTTP User-Agent string into readable browser, rendering engine, operating system, device, CPU, and crawler details. Paste a value from a request log or bug report and the results update instantly. The string is analyzed inside your browser and is not uploaded for parsing. **User-Agent strings are compatibility labels, not trusted device records.** Browsers often include several historical product tokens, so the last distinctive token usually matters more than the first. For example, Edge and Opera include a Chrome token because they use Chromium, while Chrome and Firefox on iOS report WebKit-compatible strings. This parser applies ordered rules so specific clients such as `Edg/`, `OPR/`, `SamsungBrowser/`, `CriOS/`, and `FxiOS/` win before generic Chrome or Safari rules. It also calls out reduced fields and platform ambiguities instead of presenting guesses as facts. ## How to use it 1. **Paste one User-Agent** - Copy the User-Agent header value from a browser, request log, or bug report into the input. 2. **Review the detected fields** - Read the browser or client, engine, operating system, device type, model, and CPU cards. 3. **Check the caveats** - Use the warnings to spot frozen Chromium values, ambiguous Windows versions, or unrecognized clients. 4. **Copy structured output** - Copy the JSON result for a test fixture, issue report, or local analysis script. ## Who it's for - **Developers** checking which browser and engine a request log claims before reproducing a compatibility bug. - **Support teams** turning a long User-Agent from a ticket into an OS and device summary a customer can confirm. - **Analytics engineers** spot-checking crawler, mobile, tablet, and desktop classifications before changing a reporting rule. - **Security analysts** inspecting automated client and product tokens while remembering that headers can be forged. ## Expert note Browser brands must be matched from most specific to least specific. A modern Edge string contains `Chrome/`, for example, but its later `Edg/` token identifies the browser. Chromium reduction can also freeze Android as version 10, replace the model with `K`, and expose only a major browser version. Treat missing detail as unknown, and prefer feature detection when application behavior depends on browser support. ## Frequently asked questions ### Is my User-Agent string uploaded? No. Parsing happens locally in your browser and the pasted value is not sent to a parsing service. A User-Agent can still contain device or software details, so avoid sharing sensitive request logs publicly unless you have reviewed the rest of the log data. ### Is this User-Agent parser free? Yes. You can parse User-Agent strings for free without an account, installation, or usage limit. The tool works live in the page and lets you copy the structured result as JSON. ### How long can a User-Agent string be? This tool accepts one line up to 2,048 characters, which covers normal browser, crawler, command-line client, and app User-Agent values. It rejects line breaks because an HTTP User-Agent field value should be treated as a single header value. ### Can a User-Agent identify a device exactly? Not reliably. Some mobile strings include a vendor and model, while desktop strings usually report only a broad platform. Modern browsers also reduce identifying detail, and any client can change or forge the header. Read the result as what the string claims, not verified hardware identity. ### Why does Edge or Opera contain Chrome and Safari? User-Agent strings keep compatibility tokens so websites do not reject newer clients. Chromium-based Edge and Opera include AppleWebKit, Chrome, and Safari-style tokens, then add a distinctive `Edg/` or `OPR/` token. A parser must check those specific markers before the generic Chrome marker. ### Why does Windows 11 appear as Windows 10 or 11? Windows 10 and Windows 11 commonly send the same `Windows NT 10.0` token. The classic User-Agent alone cannot separate them. Higher-entropy User-Agent Client Hints may provide more platform detail when the browser and server both support and permit that request. ### Should I use User-Agent parsing for browser support checks? Usually not. Prefer feature detection, progressive enhancement, and capability tests for application behavior. User-Agent parsing is useful for logs, diagnostics, broad analytics, crawler review, and reproducing reports, but strings can be stale, reduced, ambiguous, or intentionally spoofed. ## Related tools - [URL Parser](https://candoya.com/tools/url-parser/) - [Regex Tester](https://candoya.com/tools/regex-tester/) - [Query String Parser](https://candoya.com/tools/query-string-parser/) - [Screen Resolution Detector](https://candoya.com/tools/screen-resolution-detector/) - [JWT Decoder](https://candoya.com/tools/jwt-decoder/) --- *Markdown edition of , published for AI agents and other automated readers. Index of key pages: .*