What the browser info tool does

Every “it doesn’t work for me” bug report starts with the same questions: which browser, which version, which screen? The tool collects the answers in one table. In “My browser” mode you see navigator.userAgent, navigator.userAgentData where supported, your language list, time zone, screen and viewport size, pixel ratio, colour scheme preference, cookie and online status, CPU core and memory hints, and support for a set of web features.

“Parse a UA string” mode takes a User-Agent from a log file, an analytics tool or a customer and splits it into browser, engine, operating system and device type. Well-known crawlers such as Googlebot are flagged as bots.

How to use

  • When the page opens, “My browser” mode shows your own details; there is no button to press.
  • In a Chromium-based browser, “Request detailed Client Hints” asks for the platform version, architecture and full version list. That request only happens when you click.
  • To inspect another string, choose “Parse a UA string” and paste it; the result updates as you type.
  • Take the report with “Copy text”, “Copy JSON” or the JSON download and attach it to your support ticket.

How to read a User-Agent string

For historical reasons User-Agent strings are messy: almost every browser starts with Mozilla/5.0 and mentions other browsers too. The Chrome string below contains both AppleWebKit and Safari, yet the decisive part is Chrome/129.0.0.0:

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

That is why the parser applies ordered rules: first specific markers like Edg/, OPR/ and SamsungBrowser/, then Firefox, Chrome and Safari. The rule set is dated and not exhaustive. Some details are also frozen on purpose: Chrome reports minor versions as 0.0.0, Android strings say K instead of the model, Windows NT 10.0 covers both Windows 10 and 11, and most browsers pin the macOS version at 10_15_7 or 10.15. The tool lists these cases as notes under the result.

User-Agent Client Hints

Client Hints are a structured API designed to replace the User-Agent string. Low-entropy values (the brand list, whether the device is mobile and the platform name) can be read directly and are also sent to HTTPS sites as Sec-CH-UA headers. High-entropy values such as the platform version, architecture or device model must be requested with getHighEntropyValues(), and the browser may withhold some of them. The API is currently found mainly in Chromium-based browsers; in Firefox and Safari the field shows as not supported.

Example and interpretation

The example button parses Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Mobile Safari/537.36. Result: browser Chrome 129.0.0.0, engine Blink, OS Android 10, device type mobile, model K. The notes explain that this is a reduced string: the real Android version may be newer than 10, and K is not an actual model.

Interpretation: rather than trying to identify the device from such a string, rely on feature detection. Checking whether a CSS or JavaScript feature is supported is more robust than branching on a version number, which is why the tool includes a feature table.

Limits and privacy

User-Agent and Client Hints values can be changed by users or extensions; a bot claiming to be Googlebot is not Googlebot until a network check such as reverse DNS confirms it. Some Chromium-based browsers, Brave for example, present themselves as Chrome. Safari on iPadOS may send a desktop Mac string by default.

Everything is read in your browser and sent to no server; the tool cannot see your IP address. The share link never contains your own browser data: only the selected mode and, if you tick the option, the string you pasted in parse mode. Review the table before posting it publicly, because the combination of these values can be used for fingerprinting.

Frequently asked questions

Does this page store my information?

No. The values are read locally from APIs your browser already exposes to every site; the tool sends no request and stores nothing.

I use Windows 11, so why does it say “10 / 11”?

Both versions appear as Windows NT 10.0 in the User-Agent. In Chromium-based browsers, requesting detailed Client Hints can reveal it: a platform version of 13 or higher means Windows 11.

Why are Client Hints shown as not supported?

navigator.userAgentData is currently found mainly in Chromium-based browsers. Firefox and Safari do not offer the API, so the field stays empty; that is not an error.

How reliable is UA parsing?

It gives a good estimate for common browsers but is not definitive. Strings can be spoofed, contain frozen parts, and new browsers may be missing from the rule set. Use feature detection for critical decisions.

What goes into the share link?

Only the mode and, when “Include inputs in the link” is ticked, the string from parse mode. Your own screen, language or hardware details are never added to the link.

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