JA4 Fingerprint Directory

t13d040600_f03b13587ee1_827bd6fd5353

Completed a TLS handshake but never an HTTP request, so no User-Agent was ever presented.

What this fingerprint encodes

Transport

TCP

TLS version

TLS 1.3

Server name

server name sent

Cipher suites offered

4

Extensions offered

6

ALPN

none offered

Same tool, different options

These 2 other fingerprints share this one's JA4_c — the extension and signature-algorithm hash. A client that keeps its extension set constant while varying its cipher list produces exactly this pattern, which is what a scanner iterating cipher suites looks like. A JA3 cannot show you this: its single MD5 collapses ciphers and extensions together, so every variation looks like an unrelated client.

• t13d050600_75d938f10e26_827bd6fd5353
• t13d060600_a150a9413979_827bd6fd5353

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 4

• TLS_AES_128_GCM_SHA256
• TLS_AES_128_CCM_SHA256
• TLS_AES_128_CCM_8_SHA256
• TLS_EMPTY_RENEGOTIATION_INFO_SCSV

Extensions 6

• server_name
• supported_groups
• ec_point_formats
• signature_algorithms
• supported_versions
• key_share

Named groups 37

• x25519
• secp256r1
• secp384r1
• secp521r1
• x448
• ffdhe2048
• ffdhe3072
• SecP256r1MLKEM768
• X25519MLKEM768
• 1 (0x0001)
• 2 (0x0002)
• 3 (0x0003)
• 4 (0x0004)
• 5 (0x0005)
• 6 (0x0006)
• 7 (0x0007)
• 8 (0x0008)
• 9 (0x0009)
• 10 (0x000a)
• 11 (0x000b)
• 12 (0x000c)
• 13 (0x000d)
• 14 (0x000e)
• 15 (0x000f)
• 16 (0x0010)
• 17 (0x0011)
• 18 (0x0012)
• 19 (0x0013)
• 20 (0x0014)
• 21 (0x0015)
• 22 (0x0016)
• 26 (0x001a)
• 27 (0x001b)
• 28 (0x001c)
• ffdhe4096
• 259 (0x0103)
• 260 (0x0104)

Point formats 1

• uncompressed

771,4865-4868-4869-255,0-10-11-13-43-51,29-23-24-25-30-256-257-4588-4587-1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21-22-26-27-28-258-259-260,0

Seen in live traffic

Connections

1

First seen

2026-08-23 18:31 UTC

Last seen

2026-08-23 18:31 UTC

Transport

TCP

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.