User Agent
User Agent Parser
Analyze browser, OS, device, and engine details from any user agent string.
User Agent Parser
Analyze browser, OS, device, and engine details from any user agent string.
Parsed locally in your browser; no data leaves this page.
Parsed details
Browser, OS, device type, and engine breakdown.
Paste a user agent and click Parse to see details.
What
User Agent Parser definition
A user agent parser extracts browser, OS, and device info from a UA string.
Cases
Use Cases
1
Analyze client usage in logs
2
Detect bots or unusual devices
3
Debug UA strings from support tickets
How To
How to Analyze a User-Agent String
A step-by-step guide to extracting browser, OS, device, and engine info from User-Agent.
1
Paste UA
Paste the full User-Agent string into the input.
2
Run parser
Click Parse to analyze the string.
3
Use results
Review and copy the detected browser/OS/device/engine information.
Knowledge
Understanding User Agents
What is a User Agent?
A User Agent is a string sent by browsers and apps to identify themselves to servers. It typically includes the application name, version, operating system, and rendering engine information.
User Agent Structure
A typical UA string contains: browser name/version, rendering engine (Blink, WebKit, Gecko), OS and version, and device type indicators. Many browsers include 'Mozilla/5.0' for historical compatibility reasons.
Browser Rendering Engines
Blink powers Chrome, Edge, Opera. WebKit powers Safari. Gecko powers Firefox. Trident/EdgeHTML powered old IE/Edge. The engine affects how websites render and which features are supported.
User Agent Reduction
Modern browsers are reducing UA string detail for privacy. Chrome's User-Agent Reduction freezes certain values. Client Hints (Sec-CH-UA headers) provide granular information when requested.
Bot Detection
Crawlers and bots typically identify themselves in the UA string (e.g., 'Googlebot', 'bingbot'). However, malicious bots may spoof legitimate browser UAs, so UA-based bot detection is not foolproof.
FAQ
User agent parser FAQ
What is a user agent string?
It is the User-Agent HTTP header that identifies the browser, OS, and sometimes device making a request.
Why do Chrome and Edge look similar?
Both are Chromium-based and share Blink/WebKit tokens. The parser checks for Edge (Edg) or Opera (OPR) prefixes to separate them.
How accurate is device detection?
It relies on known patterns. Mobile vs. tablet is inferred from common keywords; some devices mask details, so results are best-effort.
Can this detect bots?
It flags known crawler keywords (bot, spider, crawl, etc.), but sophisticated bots can spoof real browsers.
What about User-Agent Reduction or UA-CH?
Newer browsers may shorten UA strings. If tokens are missing, use Client Hints headers (Sec-CH-UA*) on the server for more detail.
How can I capture a UA string from requests?
Copy the User-Agent header from your browser devtools Network panel or from server logs, then paste it here.