TOOL
User-Agent Parser
Paste a User-Agent string to identify the browser, OS, engine and device. Your own is filled in.
Processing happens locally in your browser. Nothing you type is sent to BlackhawkHub.
How to use it
Paste a User-Agent string, or click "Use my User-Agent" to fill in your browser's. The tool identifies the browser and version, the operating system, the rendering engine and the device type.
What a User-Agent is
Browsers and other clients send a User-Agent header describing themselves. It drives analytics, compatibility decisions and troubleshooting. But it is client-controlled and unreliable: anything can claim to be anything, which is why a 403 or 429 that keys on the User-Agent is weak. curl lets you set any User-Agent with -A to test such behaviour. The header's tangled "Mozilla/5.0" prefix is a historical artefact, not a real identity.
Frequently asked questions
Why do all User-Agents start with "Mozilla/5.0"?
For historical compatibility. In the 1990s servers checked for "Mozilla" to send modern HTML, so every browser began claiming it. The string is now a tangle of legacy tokens; the meaningful parts are the browser and OS identifiers later in it.
Can a User-Agent be trusted?
No. It is set by the client and can be anything. Bots, scripts and privacy tools change it freely. It is useful for statistics and troubleshooting but must never be a security control; a 403 that depends on the User-Agent is trivially bypassed.