OneTaskBy Tim King · Updated
Browser Detector
Live Screen, Pixel Ratio, Graphics Card and Feature Support, With a Copyable Report
OneTask is free, with no sign-up, and built by one person.
If this tool saved you time, a coffee helps keep new ones coming.
How the Browser Detector works
This browser detector answers "what browser am I using?" and the questions a support desk asks next: your browser and version, operating system, screen and window size, pixel ratio, display preferences, graphics card and the web features your browser supports, with a report to copy.
How the browser detector works
Everything is read live from the page, not guessed from a database. The browser and operating system come from the User-Agent string, the same text a server sees. Screen and window sizes come from the screen and window objects, display preferences from CSS media queries, the graphics card from WebGL, and each feature line checks whether the matching API exists in this browser right now.
The formula for physical pixels is CSS pixels × device pixel ratio. A screen that reports 1440 × 900 at a ratio of 2 has a 2880 × 1800 panel, and pages are laid out at the smaller size.
First example. A MacBook shows Safari 18.1, macOS, a 1512 × 982 screen at ratio 2 (3024 × 1964 physical pixels), Wide colour Yes, and WebGPU Yes on recent versions.
Second example. An Android phone shows Chrome, a 412 × 915 screen at ratio 2.63, Touch points 5, Mobile Yes, and Web Bluetooth Yes, which Safari and Firefox do not offer.
How many details can a site read without asking? Every line on this page is readable by any website without a permission prompt. That combination is what browser fingerprinting relies on, which is why some browsers round or hide values such as device memory.
Where each browser detector value comes from
| Value | Source | Notes |
|---|---|---|
| Browser | User-Agent string | Chromium-based browsers often report as Chrome |
| Operating system | User-Agent string | macOS and Windows versions are frozen |
| Mobile | userAgentData.mobile or User-Agent | Tablets may report as desktop |
| Languages | navigator.languages | Order set in browser settings |
| Time zone | Intl.DateTimeFormat | From the operating system |
| CPU threads | navigator.hardwareConcurrency | Logical processors, may be capped |
| Device memory | navigator.deviceMemory | Chromium only, rounded |
| Touch points | navigator.maxTouchPoints | 0 on most desktops |
| Cookies enabled | navigator.cookieEnabled | No means all cookies are blocked |
| Do Not Track | navigator.doNotTrack | Retired signal, rarely honoured |
| Global Privacy Control | navigator.globalPrivacyControl | Firefox, Brave and DuckDuckGo |
| Screen size | screen.width and height | CSS pixels, after scaling |
| Window size | innerWidth and innerHeight | Changes as you resize |
| Device pixel ratio | devicePixelRatio | Also changes with page zoom |
| Physical pixels | Screen size × pixel ratio | The panel's real resolution |
| Colour depth | screen.colorDepth | Usually 24-bit or 30-bit |
| Wide colour (P3) | color-gamut media query | Most Apple and recent phone screens |
| HDR | dynamic-range media query | Needs an HDR display and OS setting |
| Colour scheme | prefers-color-scheme | Follows the OS light or dark mode |
| Reduced motion | prefers-reduced-motion | OS accessibility setting |
| Graphics | WebGL renderer string | May be masked for privacy |
| WebGPU | navigator.gpu | Modern GPU API for compute and 3D |
| WebAssembly | WebAssembly object | Runs compiled code at near-native speed |
| Service workers | navigator.serviceWorker | Offline pages and installable apps |
| WebRTC | RTCPeerConnection | Video calls in the browser |
| Web Bluetooth and WebUSB | navigator.bluetooth and usb | Chromium only |
Tips and pitfalls
macOS reports version 10.15.7 in the User-Agent on every recent release, and Windows 11 reports itself as Windows NT 10.0, so the operating system version shown may be frozen rather than exact. Window size changes as you resize; reload or switch the Show setting to read it again. Download the report and attach it to a bug ticket instead of describing your setup.
FAQ
What browser am I using?
The first line under Browser and device names it with its version, such as Chrome 141 or Firefox 143. Browsers built on Chromium, such as Brave and Arc, often report themselves as Chrome because they use the same User-Agent string.
Why does it say Windows 10 or 11?
Windows 11 kept the Windows NT 10.0 token in its User-Agent, so the string alone cannot tell the two apart. Chromium browsers expose the true version through User-Agent Client Hints, which a site has to request.
Why is my screen resolution smaller than my monitor's?
Browsers report sizes in CSS pixels. With display scaling at 150% or on a high-density screen, a 2560-pixel-wide panel reports 1707 or 1280. Physical pixels shows the panel's real size.
Why is device memory or graphics hidden?
Firefox and Safari do not expose device memory, and some privacy settings mask the graphics card name. Brave and Tor Browser deliberately round or fake several values to resist fingerprinting.
Is the report sent anywhere?
No. Every value is read by JavaScript in your browser and shown only on this page. The download builds a text file locally. Nothing is uploaded, logged or stored.
See also: all Dev Utilities tools, Formatters & Validators, Data & Encoding, Security & Identifiers, SEO, Accessibility, AI.
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