Supply the claim
Send the declared client identity, the observed JA4, and any extra TLS or HTTP context you have.
API
The database, as an API.
Look up a JA4, or send what a client claims to be together with what it actually sent. Byteprint answers from ground truth: likely software, mismatch evidence, and confidence.
How this API works
Chrome and curl sent the same Chrome 150 User-Agent. Their network behavior was not the same.
What your client submits
- claimed_client
- Chrome 150.0.0.0 · Windows NT 10.0 · Win64 / x64
- user_agent
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36- observed_ja4
t12d218_76e208dd3e22_16bbda4055b2- http
- HTTP/1.1
What Byteprint compares
- claim_match
- Google Chrome 150.0.7871.129 · Windows Server 2019 Datacenter · 10.0.17763 · build 17763 · 64-bit
- expected_ja4
t13d1516h2_8daaf6152771_806a8c22fdea- fingerprint_match
- curl 8.11.0 · Windows Server 2019 Datacenter · 64-bit
- expected_http
- h2
What you get
- verdict
- identity_mismatch
- spoof_confidence
- 1.0
- likely_source
- curl 8.11.0
- source_confidence
- 0.90
SignalChrome referenceSubmitted observationResult
User-Agent
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36MatchJA4Mismatch
t13d1516h2_8daaf6152771_806a8c22fdeat12d218_76e208dd3e22_16bbda4055b2HTTP protocol
h2HTTP/1.1MismatchThe fields and confidence values shown here are illustrative, not a frozen production contract.
From request to evidence
Built for the controls you already operate.
Receive the answer
Get the likely source, mismatch reasons, confidence, and known collisions, backed by captured evidence.
Choose the action
Enrich WAF, CDN, SIEM, fraud, and investigation workflows. The policy decision stays in your system.
Private beta