User-Agent parser
Parse a User-Agent string into browser and version, rendering engine, operating system, device type and mobile flag — fully offline with a built-in rule set.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Parsed result
Safari 17.4WebKit 605.1.15iOS 17.4Mobile phoneYes (mobile)Mozilla/5.0 (iPhone; CPU iPhone OS 17_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Mobile/15E148 Safari/604.1What this tool does
- Debug compatibility reports: take the UA from a user’s bug report and see which browser and version they actually used instead of guessing.
- Make compatibility calls by checking the engine — Blink, WebKit, Gecko or EdgeHTML — to decide whether a prefix or fallback is needed.
- Tell phones, tablets and desktops apart: iPad, Tablet and Android-without-Mobile markers decide the device type, so tablets are not counted as phones.
- Spot crawler traffic: UAs containing bot, crawler, spider, curl or python-requests are labelled as a bot.
Example
Input
Mozilla/5.0 (iPhone; CPU iPhone OS 17_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Mobile/15E148 Safari/604.1
Output
Browser: Safari 17.4 Engine: WebKit 605.1.15 OS: iOS 17.4 Device type: Mobile phone Mobile: Yes (mobile)
Underscores in version numbers become dots, so iOS 17_4 in the UA shows as 17.4. An iPhone UA contains both Safari and Mobile; the rule set checks tablet markers first and then falls through to mobile, so it is never misread as a tablet.
Frequently asked questions
Why do two browsers report the same version?
The UA is a self-declared string that anyone can change. Chrome keeps the Safari and AppleWebKit fragments for compatibility, so the rules must be ordered: WeChat, QQ Browser, UC, Samsung Internet, Opera and Edge are all checked before Chrome, with Safari last as a fallback.
What does the “10/11” Windows version mean?
Windows 10 and Windows 11 both send Windows NT 10.0 and Microsoft no longer distinguishes them, so the tool shows “10/11”. NT 6.3 maps to 8.1 and 6.1 to 7 — those mappings live in the rule table.
Why are recent iPadOS or Android devices sometimes unrecognised?
Since iPadOS 13 Safari sends a desktop UA that pretends to be a Macintosh, and Android tablets may omit the Tablet token, so such UAs fall back to desktop or unknown. Use the “use current browser UA” button to see what your own environment sends.
What if the result is unknown?
The rule set only covers common browsers and systems; niche browsers, embedded WebViews and spoofed UAs return unknown rather than throwing an error. Read the raw UA for keywords yourself or cross-check with another tool.
Is the UA I paste uploaded anywhere?
No. The rules ship with the page and parsing is local — no network request is made and it works offline. Note that a UA can contain device model details, so avoid posting it publicly.
Keywords：user agentuaua 解析user-agent parser浏览器识别设备检测browser detectionnavigator.userAgent