User Agent Parser
Parse User-Agent strings into browser, engine, OS, and device, and spot crawlers such as GPTBot and ClaudeBot in your logs.
Local workspace
Named projects in IndexedDB · Local only — never synced to our servers. Worksp…
Batch workspace
Format multiple files locally in one run.
FAQ
Why does every browser claim to be Mozilla?
Servers once sniffed for Mozilla to decide which page to send, so every browser kept the token. Chrome's string still claims Mozilla, AppleWebKit, Chrome, and Safari at once, which is why the order you check matters more than the names.
How do I tell Edge from Chrome?
Edge includes both Chrome and Safari in its string and adds Edg/ at the end. Check Edge, Opera, and Samsung Internet before Chrome, or you'll label them all Chrome, which is what this parser does.
Which AI crawlers are recognized?
GPTBot, ChatGPT-User, OAI-SearchBot, ClaudeBot, Claude-User, PerplexityBot, Google-Extended, Bytespider, CCBot, Amazonbot, and meta-externalagent, alongside search, social, and SEO crawlers.
Why is the macOS version always 10.15.7?
Safari and Chrome freeze it to reduce fingerprinting, so the reported value is a floor rather than the real version. iOS and Windows report coarse values for the same reason: Windows 11 still says Windows NT 10.0.
Can I trust what a User-Agent says?
No. Any client can send any string, and scrapers routinely copy a browser's. It's fine for analytics and content negotiation, but never for security decisions or access control.