Free User Agent Parser
Updated September 2026
Parse any user agent string to identify browser, OS, device type, and rendering engine. Detect bots and crawlers — free online user agent analyser.
Diagnosing web and network issues quickly is critical for site owners, developers, and SEO professionals. The User Agent Parser delivers actionable data in seconds.
Parse any user agent string to identify browser, OS, device type, and rendering engine. Detect bots and crawlers — free online user agent analyser. Results are immediate — no waiting, no loading screens, no account required.
Who uses the User Agent Parser?
- Web developers debugging browser-specific bugs by verifying what UA string is being sent.
- Analytics engineers classifying traffic by device type using raw UA data from server logs.
- Security teams identifying bot and scraper traffic from suspicious user agent patterns.
Common uses and search terms
The User Agent Parser is frequently used for: user agent, browser detection, ua parser. Whether you need a quick result or are working through a longer project, the tool handles all common variations without any configuration.
Why use Allio Tools's User Agent Parser?
Everything runs locally in your browser. No data is sent to a server, logged, or stored anywhere. The tool is completely free with no usage limits, no premium tiers, and no account required. Available in 11 languages and optimised for all screen sizes, the User Agent Parser works on desktop, tablet, and mobile with no app download needed.
See also:IP Address Lookup · Website Speed Test · DNS Lookup
How the User Agent Parser works
Paste a User-Agent string in the input field, or click "Use My Browser's UA" to auto-fill your current browser's user agent.
Click Parse to extract browser name and version, rendering engine, operating system, device type, and mobile/bot flags.
Your own browser's UA is auto-detected and parsed on page load, so results appear immediately without any clicks.
Read the results grid for a quick pass/warn view on whether the string is flagged as a likely bot.
Tips & tricks
- There's no copy or share button for the parsed results — select the text on the page manually if you need to save or send it.
- The tool auto-parses your own browser's UA the moment the page loads, before you click anything — replace the input text and click Parse to check a different UA.
- Bot detection looks for keyword patterns (bot, crawl, spider, plus named crawlers like Googlebot/Bingbot/DuckDuckBot) — it flags matches as 'Likely a bot' but this is pattern matching, not a verified bot database.
- The rendering engine field distinguishes Gecko (Firefox), WebKit/Blink (Chrome/Safari/Edge), and Trident (old IE) — modern Chromium-based browsers all report as 'WebKit / Blink' since they share the same AppleWebKit token.
Frequently Asked Questions
What is a user agent string?
A user agent string is sent by browsers and bots in the HTTP User-Agent request header identifying the client software. Example: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
Why do all browsers include "Mozilla/5.0" in their user agent?
Historical compatibility. Early websites only served features to Netscape (Mozilla). Other browsers started including "Mozilla/5.0" to get full content. The pattern stuck — all modern browsers still include it for compatibility even though it's technically misleading.
How do I detect mobile devices from user agent strings?
Look for keywords: "Mobile" or "Android" (mobile phones), "iPad" or "Tablet", "iPhone". The parser extracts device type automatically. However, modern best practice is to use CSS media queries and feature detection instead of UA sniffing.
How can I tell if a user agent is a search engine bot?
Googlebot: "Googlebot"; Bingbot: "bingbot"; DuckDuckBot: "DuckDuckBot"; Common crawlers contain "bot", "crawl", "spider", plus specific patterns for Facebook/WhatsApp/Twitter link-preview bots. The tool flags any of these automatically as 'Likely a bot'.
Can user agents be spoofed?
Yes, trivially. Any client can send any User-Agent string. Never rely on UA strings for security decisions. They're useful for analytics and feature detection, but should not gate access to secure resources.
Is my data safe when using the User Agent Parser?
Completely safe. The User Agent Parser processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.
How current is the data returned by the User Agent Parser?
The User Agent Parser fetches live data in real time each time you run it. Results reflect the current state of the server or domain at the moment of the request.
Why does the User Agent Parser sometimes return different results than other tools?
Results depend on the real-time state of the target server and DNS propagation, which can vary by geographic region and caching TTL. If you see inconsistencies, wait a few minutes and re-test — DNS changes can take up to 48 hours to propagate fully worldwide.
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