What does "What is my browser" show?
This tool reads the details your web browser shares with every site you visit and lists them in one place: the user agent string, platform, preferred languages, cookie and online status, screen resolution, viewport size, device pixel ratio, color depth and timezone. It's handy for bug reports, support tickets and checking how a site sees your device.
How to use it
- Click Generate. There's nothing to type.
- Read the eleven lines in the output box.
- Click Copy to paste the whole block into a bug report or a message to support.
If you resize the window or move it to another monitor, click Generate again. The values are read once per click, not continuously.
What each line means
Every value comes from a standard browser API. Here's where each one comes from and what it's good for:
| Line | Source | What it tells you |
|---|---|---|
| User agent | navigator.userAgent |
The identification string your browser also sends in the User-Agent header |
| Platform | navigator.platform |
A legacy OS hint such as Win32, MacIntel or Linux x86_64 |
| Language / Languages | navigator.language, navigator.languages |
Your preferred language first, then the full preference list from your browser settings |
| Cookies enabled | navigator.cookieEnabled |
Whether the browser allows cookies at all |
| Online | navigator.onLine |
Whether the browser thinks it has a network connection |
| Screen resolution | screen.width × screen.height |
Your display size in CSS pixels |
| Viewport size | window.innerWidth × window.innerHeight |
The visible area of this page, including scrollbars |
| Device pixel ratio | window.devicePixelRatio |
How many physical pixels make up one CSS pixel |
| Color depth | screen.colorDepth |
Bits per pixel, usually 24 |
| Timezone | Intl.DateTimeFormat().resolvedOptions().timeZone |
An IANA zone name such as Europe/London |
Reading a user agent string
The tool shows the raw string rather than a parsed "You're using Chrome 140" summary, because the string is what a website's server actually receives. A typical desktop Chrome string looks like this:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36
Most of it is historical. Nearly every browser starts with Mozilla/5.0, and Chrome mentions Safari and Gecko for compatibility with old sites that checked for them. The parts that matter are the platform in brackets and the last browser token with a version: Chrome/… for Chrome, Edg/… for Edge, Firefox/… for Firefox, and Version/… Safari/… for Safari.
Some of these details are no longer precise. Chromium's User-Agent Reduction froze the minor version to 0.0.0, Windows to Windows NT 10.0 and macOS to Mac OS X 10_15_7, whatever you're actually running. Sites that need exact versions are expected to request them through User-Agent Client Hints instead.
Screen, viewport and pixel ratio
These three numbers are the ones web developers ask for most often when a layout breaks on one machine but not another.
All sizes are in CSS pixels. With display scaling turned on, a 2560 × 1440 monitor at 150% scaling reports a screen of about 1707 × 960 and a device pixel ratio of 1.5. Browser zoom changes the numbers too: in Chrome and Firefox, zooming in to 200% roughly halves the viewport width and doubles the pixel ratio, which is worth knowing before you report "the site thinks my screen is tiny".
The viewport is what CSS media queries use. If a responsive page shows its mobile layout on your laptop, compare the viewport width with the site's breakpoints rather than with your screen resolution.
Privacy and what's not shown
Every value here is visible to any website you open, without a permission prompt. Combined, they can help sites tell visitors apart, which is one reason browsers have started trimming the user agent. The tool doesn't show your IP address, location, installed fonts or plugins, and it doesn't send anything to a server.
Photos can leak more than your browser does. The EXIF viewer shows the camera details and GPS data hidden in a JPEG, and the EXIF remover strips them before you share it. If you're writing your own feature-detection script, draft it in the JavaScript editor, which highlights and formats code but doesn't run it.
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