Paste any UA string or use your current browser's UA below
Paste a user agent string
Click Parse to decode browser, OS, device & engine info// decode any user agent string instantly
Parse and decode any user agent string instantly. Detect browser, OS, device type, engine, and version from UA strings. Free, browser-based, no sign-up required.
Paste a user agent string
Click Parse to decode browser, OS, device & engine infoYour current browser's UA string is pre-loaded. Or paste any UA string you want to analyze.
Hit the Parse button to instantly decode the UA string into structured components.
View browser name, OS, device type, and rendering engine. Copy the JSON output for your app.
A User Agent Parser decodes the User-Agent HTTP header string that browsers send with every request. This string identifies the browser, operating system, device type, and rendering engine — all packed into one line of text.
A user agent string is a text identifier that browsers and other HTTP clients send in request headers. It tells the web server which browser, operating system, and device is being used. For example, Chrome on Windows sends a string starting with Mozilla/5.0 (Windows NT 10.0; Win64; x64)...
This is a legacy quirk of web history. Originally, only Netscape (Mozilla) supported certain features, so other browsers started spoofing the Mozilla prefix to receive the same content. The pattern stuck and is still used today even though it's technically misleading.
Yes — user agent strings typically include keywords like Mobile, Android, or iPhone for mobile devices, and iPad for tablets. However, UA-based detection can be unreliable if users spoof their UA. Feature detection via JavaScript is more robust for production apps.
Your current browser's UA string is automatically loaded in this tool when you open it. You can also find it by opening your browser's DevTools console and typing navigator.userAgent, or by searching "what is my user agent" in any browser.
Yes, any HTTP client can set any user agent string it wants. Malicious bots often spoof Chrome or Firefox UA strings to avoid detection. However, legitimate crawlers like Googlebot typically identify themselves honestly and can be verified via reverse DNS lookup.
Generally no — UA sniffing is considered a fragile approach. Browser strings are inconsistent and easily spoofed. For feature detection, use JavaScript APIs like navigator.maxTouchPoints or CSS media queries. UA parsing is still useful for analytics, logging, and server-side bot filtering.
A User Agent Parser is a tool that decodes the User-Agent HTTP header string into human-readable, structured information. Every time a browser, bot, or HTTP client makes a request to a web server, it sends a User-Agent string that identifies itself. This string is a compact, often cryptic text blob — and parsing it reveals the browser name, browser version, operating system, device type, and rendering engine used.
Our User Agent Parser handles this decoding instantly in the browser. Paste any UA string and you'll immediately see a breakdown of all its components, plus a raw JSON output you can copy directly into your application.
A typical modern Chrome user agent string 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
Breaking this down:
While modern web development favors feature detection over UA sniffing, user agent strings remain critically important in several scenarios:
Our parser identifies all major browsers including Chrome, Firefox, Safari, Edge, Opera, Brave, Vivaldi, Samsung Internet, UC Browser, DuckDuckGo Browser, Yandex Browser, and legacy browsers like Internet Explorer. It correctly handles the complex overlap in Chromium-based browsers where multiple browser names appear in the same string.
The parser detects Windows (with NT version mapping to marketing names like XP, Vista, 7, 8, 10/11), macOS, Linux, iOS, iPadOS, Android, Windows Phone, Chrome OS, and FreeBSD. Windows NT version codes are translated to their familiar names — for example, Windows NT 6.1 maps to Windows 7.
Devices are classified as Desktop, Mobile, Tablet, Smart TV, or Console. Detection relies on keywords in the UA string — iPhone and Android (without tablet identifiers) map to Mobile, iPad maps to Tablet, and the absence of mobile keywords typically indicates Desktop.
The parser identifies the underlying rendering engine: WebKit (Safari, Chrome, Edge), Gecko (Firefox), Trident (Internet Explorer), and legacy Presto (old Opera). Knowing the engine is valuable for diagnosing CSS rendering differences that persist even across different browser brands built on the same engine.
The parser detects well-known bots including Googlebot, Bingbot, Yahoo Slurp, DuckDuckBot, Baiduspider, YandexBot, Facebookbot, and common scripting clients like curl, wget, and python-requests. When a bot is detected, a prominent alert is displayed alongside the parsed results.
It's important to understand that UA parsing is inherently imprecise. Browsers frequently include compatibility tokens from other browsers (Chrome includes "Safari" in its UA, Safari includes "Mozilla"), strings can be spoofed by any client, and new browser versions may not be recognized by parsers with outdated patterns. For production applications requiring reliable device detection, consider combining UA parsing with client-side feature detection APIs.