What Is My User Agent?

Every request your browser makes carries a user-agent string, a short text that announces your browser, its version, and your operating system to every website you visit. Below is yours, exactly as servers receive it, decoded into plain language. Everything on this page is read locally by your browser: nothing is sent to our servers.

What is a user agent?

A user agent is the identity card your browser presents with every HTTP request. The string follows a format inherited from the 1990s (which is why virtually every browser still claims to be "Mozilla/5.0") and packs in the browser name and version, the rendering engine, and the operating system. Servers read it before sending you anything.

What do websites use it for?

Three things, mostly. Adapting content: serving a mobile layout to a phone or warning you that your browser is outdated. Analytics: counting which browsers and systems visit a site. Filtering: blocking known bots and scrapers that announce themselves honestly. Because the user agent is so widely abused for tracking, modern browsers have started freezing or reducing it. Chrome, for example, no longer reveals your exact Android version or device model by default.

User agents and browser fingerprinting

Your user agent alone is shared with thousands of other people running the same browser on the same system, so by itself it doesn't identify you. The privacy risk appears when sites combine it with other signals visible on this page: screen resolution, time zone, language, touch support, installed fonts, and more. Together these can form a fingerprint unique enough to track you without cookies. The user agent is one piece of that puzzle, which is why pairing a privacy-hardened browser with a VPN matters more than masking any single value.

→ What websites can see from your IP · → How to hide your IP

Frequently asked questions

Can I change my user agent?

Yes. Every major browser lets you override it through developer tools, and extensions can switch it permanently. It's useful for testing websites, but expect breakage: sites that adapt to your declared browser will serve the wrong experience, and pretending to be another device doesn't change what your browser can actually do.

Is my user agent unique to me?

On its own, no: millions of people share the exact same string. But combined with your screen size, language, time zone, and other browser properties, it contributes to a fingerprint that can be nearly unique. That combination, not the user agent itself, is what tracking scripts exploit.

Why does my user agent say Mozilla when I use Chrome?

History. In the 1990s, servers sent advanced pages only to Netscape, which identified as "Mozilla". Every browser since has claimed the same token to avoid being served degraded content. Chrome also mentions Safari and WebKit for the same compatibility reasons. The string is a fossil record of the browser wars, not a bug.