// network

what is JA4 TLS fingerprint?

JA4 is the successor to JA3: a human-readable TLS ClientHello fingerprint of the form <a>_<b>_<c>. The <a> segment encodes transport/version/SNI/cipher-count/extension-count/first-ALPN; <b> hashes the cipher list; <c> hashes the extension + signature-algorithm list.. curl-impersonate/datacenter and nodriver/residential share the full JA4 t13d1516h2_8daaf6152771_d8a2da3f94cd — a clean Chrome-stack match. playwright-cdp-launch/none shares JA4_a+JA4_b (t13d1516h2_8daaf6152771) but its extension hash diverges (e5627efa2ab1) — a headless-Chrome tell. camoufox (Firefox engine) yields a distinct JA4 t13d1715h2_5b57614c22b0_3d5424432f57 — 17 extensions and Firefox cipher ordering.