User Agent Parser
Network
The User-Agent header is the messy, free-form string browsers send to identify themselves. This parser uses pragmatic regex matching (the same approach as ua-parser-js) to extract the browser name + version, rendering engine, OS + version, device type/vendor/model, and CPU architecture. Auto-fills with your current browser's UA on load. Useful for analytics debugging, bot identification, and understanding what your server logs are seeing.
Paste a User-Agent string above.
Parsing runs entirely locally. Regex-based — same approach as ua-parser-js, with simpler rules and recent bot signatures (GPTBot, ClaudeBot, PerplexityBot).
How to use
- By default, your own browser's User-Agent is parsed.
- Click 'Use current' to refresh from `navigator.userAgent`, or paste any UA string.
- Read the parsed fields. Bots get a special highlight.
Frequently asked questions
- Why are user-agent strings so weird?
- Historical compatibility hacks. Every browser pretends to be 'Mozilla/5.0' because old servers gated content on that string. Chrome adds 'Safari' because old WebKit detection used that. The cargo cult never ends.
- Will Client Hints (UA-CH) replace this?
- Slowly. Chrome is freezing UA contents (User-Agent Reduction) and offering structured Client Hints headers (Sec-CH-UA-*) as the replacement. For now, both coexist. This parser works on the legacy UA string.
- How accurate is bot detection?
- Reliable for honest bots (Googlebot, Bingbot, GPTBot, ClaudeBot — they identify themselves). Useless against bad-faith bots that spoof a desktop Chrome UA. For those you need behavioral fingerprinting or CAPTCHAs.
- Why doesn't it show device model on iOS?
- iOS user agents have not included a specific model since iOS 13 — they all say 'iPhone' or 'iPad'. Apple deliberately strips this for privacy. Server-side, you'd use a separate Client Hint or the screen dimensions to guess.
Related tools
MAC to EUI-64 / Link-local
Convert any MAC address into its modified EUI-64 interface ID and the matching IPv6 link-local address — the same form Windows / Linux compute automatically.
URL Query Builder
Build URLs by combining a base address with editable key-value query parameters — each pair toggleable, properly percent-encoded.
IP Address Inspector
Type an IPv4 or IPv6 address and see its class, scope (private / public / loopback / link-local), decimal value, binary, reverse-DNS notation, and /32 CIDR.
Port Number Reference
Searchable cheat sheet for ~60 standard TCP / UDP port numbers — from 22 (SSH) and 80 (HTTP) to 6379 (Redis) and 27017 (MongoDB).
DNS Record Reference
Searchable cheat sheet for DNS record types — A, AAAA, CNAME, MX, TXT, NS, SOA, PTR, SRV, CAA, DNSSEC, SVCB / HTTPS — with examples.
Subnet Calculator (IPv4 / CIDR)
Parse an IPv4 CIDR into network address, broadcast, netmask, wildcard, host range, and class. Shows binary breakdown and private/public status.