What Is My User Agent
See your browser user-agent string plus local browser, platform, language, and screen details.
About the What Is My User Agent
Your user agent is a short line of text your browser sends with every request so websites know what kind of software is visiting. This tool shows you that exact string, plus a handful of related details your browser exposes — the platform you're on, your language setting, screen and window size, whether cookies are enabled, and whether you're currently online. Everything here is read locally by JavaScript running in your own browser; the values are never uploaded, logged, or sent to any server.
Knowing your user agent is useful for debugging a website that behaves oddly, filing a bug report that a developer can reproduce, checking that a browser extension or "user-agent switcher" is actually working, or confirming which browser and version you're really running. Because the reading happens on your device, the answer is instant and always reflects the browser you're using right now.
How to use
- Open the tool. As soon as the page loads, it reads your browser's own
navigatorandscreenvalues and displays them. Until that finishes you'll briefly see a "Detecting…" message. - Read your user agent. The full user-agent string appears at the top in a monospace box so every character is easy to read.
- Copy it. Click Copy user agent to place the string on your clipboard — handy for pasting into a bug report, a support chat, or a compatibility form.
- Check the details table. Below the string you'll find your platform, language, screen resolution, current viewport size, cookie status, and online status.
- Resize to watch the viewport update. The viewport row reflects your browser window's inner size and updates live as you drag the window smaller or larger.
What the user agent reveals
The user-agent string is a compact summary of your browsing environment. Reading left to right, it typically encodes:
- Browser engine and version — for example the
Mozilla/5.0prefix (a historical compatibility token every browser still sends), followed by engine markers likeAppleWebKit,Gecko, orBlink. - Browser name and version — tokens such as
Chrome/…,Firefox/…,Safari/…, orEdg/…identify the actual browser and its release. - Operating system and platform — such as
Windows NT 10.0,Macintosh; Intel Mac OS X,X11; Linux,iPhone, orAndroid, sometimes with an architecture hint. - Device hints — mobile browsers often include
Mobileor a specific device family so sites can serve a touch-friendly layout.
The extra rows in the details table come from separate browser properties: navigator.platform, navigator.language, screen.width/screen.height, window.innerWidth/window.innerHeight, navigator.cookieEnabled, and navigator.onLine. Modern browsers have started trimming or freezing parts of the user-agent string to reduce fingerprinting, so two people on very different setups can share an identical string — treat it as a strong hint, not a guaranteed fact.
Frequently asked questions
Is my user agent sent to your server?
No. This tool reads the value directly from your browser and displays it on the page. Nothing is transmitted, stored, or logged — close the tab and nothing remains.
Why does my user agent mention browsers I don't use?
Almost every browser still begins its string with Mozilla/5.0 and includes tokens like AppleWebKit, KHTML, Gecko, or Safari even when you're not using those browsers. These are legacy compatibility tokens kept for historical reasons, and they're normal.
Can I change or spoof my user agent?
Yes. Browser developer tools and dedicated extensions can override the string your browser sends. If you've enabled one of those, this tool will show the spoofed value, because it simply reports whatever your browser currently presents.
Why is the viewport size different from my screen resolution?
Screen resolution is the full size of your monitor in pixels, while the viewport is only the area inside your browser window where the page renders. The viewport is smaller because it excludes toolbars, tabs, scrollbars, and any space the window doesn't occupy — and it changes as you resize the window.
What does "cookies enabled" actually mean?
It reflects navigator.cookieEnabled, a quick indicator of whether your browser will accept cookies at all. It's a general signal rather than a per-site guarantee, since individual sites or extensions can still block cookies selectively.
Does the online status mean I have a working internet connection?
Not necessarily. navigator.onLine reports whether the browser believes it has a network connection, but it can read "Online" even when a captive portal or firewall is blocking real traffic. Use it as a hint, not a definitive connectivity test.