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User Agent Checker

Every time your browser requests a web page, it sends a "user agent" string — a line of text that identifies your browser, operating system, and device type. This tool shows your current user agent and can parse any user agent you paste to identify the browser, OS, version, device type, and rendering engine. Useful for web developers debugging compatibility issues, testing responsive designs, or understanding analytics data.

What the User Agent Tells Websites

Browser name and version — Chrome, Firefox, Safari, Edge, etc. Operating system — Windows, macOS, Linux, Android, iOS, ChromeOS. Rendering engine — Blink (Chrome/Edge/Opera), WebKit (Safari), Gecko (Firefox). Device type — Desktop, mobile, tablet, or bot/crawler. Device model — Sometimes specific devices like "iPhone" or "Pixel 8" are identified. This info helps websites serve appropriate content (mobile layout for phones, desktop layout for computers) and log analytics data about visitor devices.

How Developers and Marketers Use This

On the engineering side, the user-agent string is what a server-side stack reads when it needs to make a runtime decision: serve a different image format to Safari versus Chrome, gate an experimental WebGPU code path to Chromium 121 or newer, decide whether to render a download prompt or an inline preview, or skip a third-party widget that is known to break on older mobile browsers. Reading the structured fields directly is faster than parsing the raw string in application code, and the breakdown shown here matches what the standard user-agent parsing libraries produce.

On the marketing and analytics side, the user-agent is also how server logs and bot-detection systems decide whether a request is a real visitor or a crawler. Search-engine bots, ad-verification bots, link-checker bots, and scraping bots all identify themselves in the user-agent — and a non-trivial share misrepresent themselves as a standard browser. Comparing the user-agent string against the IP-level rDNS, the supported feature set, and the navigator entropy is the standard way to confirm whether a request is genuinely from the browser it claims to be. Use this checker to inspect the exact string your own browser sends, and to spot the difference between what a real user looks like and what an automated client claiming to be that user looks like.

Frequently Asked Questions

What is a user agent?+
A user agent is a string sent by your browser to every website you visit. It identifies your browser name and version, operating system, and sometimes device type. Websites use it to tailor content or check compatibility.
Can I fake my user agent?+
Yes. Most browsers allow user agent spoofing via developer tools or extensions. Some devices, like iPads in 'Request Desktop Site' mode, automatically send a different user agent.
Is my user agent private?+
Your user agent is sent to every website automatically. It's not a unique identifier, but combined with other data (screen size, fonts, etc.) it can contribute to browser fingerprinting.
Why does my user agent contain 'Mozilla'?+
All modern browsers include 'Mozilla/5.0' for historical compatibility. Early websites checked for Mozilla to serve modern content, so other browsers adopted the prefix. It no longer means you're using Firefox.
What does the tool tell me about my browser?+
Browser name and version, rendering engine (Blink, Gecko, WebKit), operating system, device type (desktop/tablet/mobile), CPU architecture (when reported), and whether you’re on a bot/crawler user agent.
Why are some browsers identifying as Chrome?+
User-Agent freezing — Apple, Microsoft Edge, and others spoof their UA as Chrome to maximise compatibility with sites that sniff. The tool detects this and reports the actual underlying browser when possible (via Client Hints).
How accurate is OS detection on iOS Safari?+
Increasingly imperfect — iPadOS 13+ reports as macOS Safari to claim desktop sites. The tool uses touch-event detection and screen-size heuristics to distinguish iPad from Mac when the UA is ambiguous.
Can I check the user agent of a specific URL?+
No — the tool only inspects the browser viewing it. To check what UA a bot or different browser sends to your server, use the network tab of your browser’s DevTools while accessing the page.

📖 Learn More

Related Guide User Agent Checker: Complete Guide →

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