JA4 q13d0312h3_55b375c5d22e_d3a2dad44cbf

q13d0312h3_55b375c5d22e_d3a2dad44cbf

Presented a User-Agent we cannot attribute to a known client.

What this fingerprint encodes

Transport

QUIC

TLS version

TLS 1.3

Server name

server name sent

Cipher suites offered

3

Extensions offered

12

ALPN

h3

The hello it was computed from

Recovered because the proxy now stores the pre-hash JA3 string alongside the digest. Every number below came out of this client's ClientHello; anything we cannot name in the IANA registry is shown as its raw value rather than guessed at.

Version

TLS 1.2

Cipher suites 3

• TLS_AES_256_GCM_SHA384
• TLS_CHACHA20_POLY1305_SHA256
• TLS_AES_128_GCM_SHA256

Extensions 12

• application_layer_protocol_negotiation
• quic_transport_parameters
• server_name
• key_share
• signature_algorithms
• compress_certificate
• supported_groups
• supported_versions
• ec_point_formats
• psk_key_exchange_modes
• extended_master_secret
• status_request

Named groups 3

• SecP256r1MLKEM768
• secp384r1
• secp256r1

Point formats 1

• uncompressed

771,4866-4867-4865,16-57-0-51-13-27-10-43-11-45-23-5,4588-24-23,0

Seen in live traffic

Connections

3

First seen

2026-09-21 00:53 UTC

Last seen

2026-09-21 01:59 UTC

Transport

QUIC

JA3 hashes absorbed

3

The same client, 3 different JA3s

This one JA4 covers 3 distinct JA3 hashes. A JA3 hashes the cipher and extension lists in the order they arrived, so a client that shuffles them — which Chrome and its derivatives do on purpose — produces a new JA3 almost every connection and fragments into what looks like 3 unrelated clients. JA4 sorts those lists before hashing, which is why all of it lands here instead.

• 6c8f80d63074a27381ea65c4151467a8
• 91f334d9149a1e9c87f218bd57e17f44
• e8e671fe10b262114e8c02e38bc0fce6

User-Agents seen on this fingerprint

• h3-get/1.0 (quinn+h3) 3×

A User-Agent is self-declared and trivially forged, so this names an observation rather than proving an identity. It is still the strongest signal available: the fingerprint comes off the TLS handshake and the User-Agent off the request that followed, and one client build keeping a stable JA4 while changing what it calls itself is a finding in its own right.

This entry is an observation, not a policy decision. It is here because the edge saw it, not because anyone reviewed it, and it blocks nothing on its own. Only the curated tier drives classification and banning.