What Is My Browser

What Is My Browser detects and displays your complete browsing environment automatically, the moment the page loads. No input is required. The tool reads the HTTP headers and browser properties your device sends with every web request and presents them in a readable format: browser name and version, operating system, platform, user agent string, language preferences, cookie status, and screen resolution.

This information is sent to every website you visit by your browser — it is not private information. The purpose of this tool is to make it easy to read and share these details, which are commonly needed when reporting a technical problem, verifying a browser before testing a website, or confirming that a device's configuration is correctly set up.

What the tool detects — all seven fields explained

The tool automatically detects and displays seven pieces of environment information. The table below explains what each field shows and why it is useful:

What is a user agent string?

The user agent string is a short line of text that your browser automatically sends to every website you visit as part of the HTTP request headers. It identifies your browser, its version, your operating system, and the rendering engine being used. Websites and web servers read this string to deliver appropriate content, detect mobile devices, log visitor statistics, and in some cases adjust how a page behaves based on the browser's known capabilities.

The user agent string is not human-readable at first glance — it looks like a compact technical description. But each component has a specific meaning. Understanding the structure helps when you need to report your environment to a developer or support team, or when you are investigating a browser-specific problem.

The user agent string always starts with Mozilla/5.0 — even in Chrome, Edge, Firefox, and Safari. This is a historical compatibility token that has nothing to do with the Mozilla browser. It dates from the 1990s browser wars, when servers delivered full content only to browsers that identified as Mozilla-compatible. Every browser since has included it to ensure compatibility with servers that check for it. It does not indicate that you are using a Mozilla product.

How to read a user agent string — anatomy

A typical Chrome user agent string on Windows looks like this:

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

The table below breaks down each component of a typical user agent string and what it actually means:

User-Agent reduction (2023–2025): Google began reducing the information exposed in Chrome's user agent string as part of a privacy initiative. Minor version numbers, operating system patch versions, and specific device model names are now replaced with generic placeholders. For example, Chrome on Android used to show the exact device model (e.g. Pixel 9) and Android version — it now shows Android 10 and device model K as fixed values, regardless of the actual device. If your user agent string shows Android 10 or an operating system version that seems wrong, this is likely User-Agent reduction in action. The major browser version number is still accurate. Servers that need more precise environment information can request it via the newer User-Agent Client Hints mechanism.

Major browsers and their rendering engines

All modern browsers fall into three rendering engine groups, which is the most important categorization for cross-browser compatibility. Two browsers using the same rendering engine (both Chrome-based, for example) will behave identically in almost all cases. Browsers using different engines may render the same HTML and CSS differently, support different browser APIs, and exhibit different JavaScript behavior.

Practical use cases

Reporting a technical problem to a support team

When something goes wrong on a website — a layout breaks, a button does not work, a form submission fails, a video does not play — support teams and developers need to know the exact environment where the problem occurred. The browser name alone is rarely sufficient. The browser version matters because bugs are often introduced or fixed in specific releases, and the combination of browser version and operating system determines which rendering engine version is in use. Instead of writing 'I use Chrome', sharing the full output of the What Is My Browser tool gives support teams all the context they need to reproduce the issue.

Cross-browser and cross-device QA testing

Web developers and QA testers systematically test websites across different browser and OS combinations to identify rendering differences, layout problems, and functional failures. The What Is My Browser tool provides a fast way to confirm the exact environment of a test device before logging a test result. When testing on multiple physical devices (a Windows desktop, a MacBook, an Android phone, an iPad), quickly checking each device's browser info at the start of a test session ensures results are correctly attributed to the right environment.

Diagnosing browser-specific website issues

Some website problems only affect specific browsers or specific browser versions. CSS features like flexbox gaps, grid subgrid, container queries, and certain color functions have varying levels of support across browsers and versions. JavaScript APIs have different availability timelines. If a problem only appears for some users, checking what browser and version those users share is the first step to isolating the cause. The What Is My Browser tool lets any user — including non-technical users who may not know how to find their browser version through settings — retrieve and share this information in one step.

Verifying language settings for localization issues

If a website is displaying content in the wrong language, or if a localization feature (date format, currency, number formatting) is behaving unexpectedly, the browser's language preferences are frequently the cause. The Languages field in the tool output shows the exact Accept-Language values your browser sends. If a user reports being served French content when they expect English, checking their browser language settings — via the Languages field in this tool — is the fastest way to confirm whether the browser's language preference is the source of the issue.

How to change or spoof your user agent for testing

Developers and QA testers sometimes need to simulate a different browser environment — for example, to see how a website behaves when visited by a mobile browser, to test mobile-specific layouts on a desktop machine, or to check how a server responds to a specific user agent. This is called user agent spoofing or user agent switching.

In Chrome and Edge, open DevTools (F12 or Ctrl+Shift+I), go to the Network tab, click More network conditions, and uncheck 'Use browser default' under User Agent. You can then type any custom user agent string. In Firefox, open DevTools, switch to Responsive Design Mode (Ctrl+Shift+M), click the settings icon, and add a custom user agent. After changing the user agent, reloading the page sends the new string to the server.

Changing your user agent affects how the server identifies your browser, but it does not change your browser's actual rendering capabilities. If you spoof a Safari user agent in Chrome, the server will respond as if you are using Safari — but your browser will still render the page using Chrome's Blink engine, not Safari's WebKit engine. For genuine cross-browser rendering tests, you need to test in the actual browser, not just spoof its user agent string.

Usage limits

Related tools

• Spider Simulator — see how a search engine crawler views your page, including what text, links, and meta tags are visible in the HTML source.
• SSL Checker — verify that your site's HTTPS certificate is valid and correctly configured for the domain you are testing.
• Check GZIP Compression — confirm whether your web server is compressing resources before delivering them to your browser.
• Websites Broken Link Checker — identify broken links on a site, useful when investigating why certain pages are not loading correctly.

Frequently asked questions

What information does the What Is My Browser tool show?

The tool automatically detects and displays seven pieces of information about your current browsing environment: browser name (Chrome, Firefox, Safari, Edge, etc.), browser version number, the full user agent string sent by your browser, platform and operating system (Windows, macOS, Android, iOS, etc.), browser language preferences, whether cookies are enabled or disabled, and screen resolution. All of this information is read from the HTTP headers and browser properties your device sends automatically — no input is required.

What is a user agent string?

A user agent string is a line of text your browser sends to every website you visit, embedded in the HTTP request headers. It identifies your browser name, version, operating system, and rendering engine. Websites read this string to determine what browser you are using, detect mobile devices, and in some cases adjust their behavior based on the browser's known capabilities. The string is structured but not human-readable at first glance — it begins with Mozilla/5.0 (a compatibility token present in all modern browsers) followed by the operating system, rendering engine, and actual browser identification.

Why does my user agent start with Mozilla/5.0?

All modern browsers include Mozilla/5.0 at the start of their user agent string for historical backwards-compatibility reasons. In the 1990s, early web servers only delivered their full feature-rich content to browsers that identified themselves as Mozilla-compatible (the dominant browser at the time was Netscape Navigator). All subsequent browsers adopted the Mozilla/5.0 prefix to avoid being served degraded content by these servers. Today it is a vestigial compatibility token with no practical meaning — it does not indicate that you are using a Mozilla product.

Why does my user agent show Chrome/124.0.0.0 with all zeros?

Google began reducing the detail in Chrome's user agent string in 2023 as part of a privacy initiative to reduce browser fingerprinting. Minor version numbers (previously shown as Chrome/124.0.6367.82, for example) are now always displayed as zeros — Chrome/124.0.0.0. Only the major version number is still accurate. Similarly, Android device models and OS patch versions are now replaced with generic placeholders. If you need precise version information, Google's User-Agent Client Hints mechanism allows servers to request it separately from the standard user agent header.

Is my personal data being collected when I check my browser info?

No. The information displayed is technical browser and device data — browser name, version, operating system, user agent string, screen resolution, language preferences, and cookie status. This is the same information your browser sends to every website you visit automatically, embedded in HTTP request headers. It is not personal data in the sense of names, email addresses, passwords, or account details. The tool reads and displays it for your own reference; no personal information is stored or linked to your identity.

Can I use this tool on mobile?

Yes. The tool works on any device — desktop, laptop, tablet, or mobile phone — and detects device-specific information including the mobile browser's user agent string, the mobile operating system (Android or iOS) and version, and the screen resolution of the device. Mobile and desktop versions of the same browser (Chrome on Android versus Chrome on Windows, for example) send different user agent strings and are detected separately.

Why do I need to know my browser version?

Browser version information is needed for three main situations: reporting a website problem to a support team (developers need the exact version to reproduce browser-specific bugs), verifying compatibility before installing a browser extension or web application that requires a minimum version, and checking whether your browser needs updating to access features or security patches. Knowing your version is also useful when following a technical tutorial that specifies a minimum browser version requirement.

Is the What Is My Browser tool free?

Yes. The tool is free within the daily usage limits. Guest users can run 25 checks per day without creating an account. Registering a free ToolsPiNG account increases the daily limit to 100 checks and gives access to usage history and saved favorites. Since the tool displays your current browser's information automatically, most users will only need to check it once per session.