TLS ClientHello (JA4)

t13d3013h2_1d37bd780c83_8537cf56674e

first seen 2026-06-18 14:20 · last seen 2026-09-16 20:50 · JSON

Inconsistencies

User-Agents observed with this fingerprint that contradict what it proves at the wire. all inconsistencies →

fingerprint User-Agent claims wire shows confidence seen first seen last seen

t13d3013h2_1d37bd780c83_8537cf56674e

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:151…

User-Agent claims Firefox 151.0

TLS cipher list matches no measured Firefox capture

The offered TLS cipher suites match no controlled capture of Firefox. Cipher lists are very stable per browser, so a different one is a real inconsistency — though a TLS-inspecting proxy re-originating the handshake is an honest cause, which holds this at medium.

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:151.0) Gecko/20100101 Firefox/151.0
Claimed version	151.0
Measured versions	146.0.1, 152.0.1, 154.0, 140.0.2, 151.0.4, 151.0.2, 139.0, 153.0.1, 155.0, 152.0.5, 153.0.3, 142.0.1, 153.0.4, 152.0.6, 150.0.2, 135.0, 132.0, 152.0.3, 148.0.2, 137.0, 141.0, 155.0.1, 153.0, 151.0.3, 144.0.2, 154.0.1, 134.0, 152.0.4, 151.0
Layer	cipher suites differ
JA4 label	unlabeled

medium

2026-07-03

Last 7 days (8 observations)

Distinct clients per day (last 30 days, peak 155/day)

Distinct clients are counted by IP-hash per complete UTC day — unlike observation counts this is insensitive to one chatty client, but NAT merges clients and address rotation splits them.

Decomposed attributes

Protocol	`t (TLS over TCP)`
TLS version	`13`
SNI	`d (domain)`
Cipher count	`30`
Extension count	`13`
ALPN	`h2`
Ciphers	`002f, 0033, 0035, 0039, 003c, 003d, 0067, 006b, 009c, 009d, 009e, 009f, 1301, 1302, 1303, c009, c00a, c013, c014, c023, c024, c027, c028, c02b, c02c, c02f, c030, cca8, cca9, ccaa`
Extensions	`000a, 000b, 000d, 0016, 0017, 001b, 002b, 002d, 0031, 0033, ff01`
Signature algorithms	`0905, 0906, 0904, 0403, 0503, 0603, 0807, 0808, 081a, 081b, 081c, 0809, 080a, 080b, 0804, 0805, 0806, 0401, 0501, 0601, 0303, 0301, 0302, 0402, 0502, 0602`
JA4_r	`t13d3013h2_002f,0033,0035,0039,003c,003d,0067,006b,009c,009d,009e,009f,1301,1302,1303,c009,c00a,c013,c014,c023,c024,c027,c028,c02b,c02c,c02f,c030,cca8,cca9,ccaa_000a,000b,000d,0016,0017,001b,002b,002d,0031,0033,ff01_0905,0906,0904,0403,0503,0603,0807,0808,081a,081b,081c,0809,080a,080b,0804,0805,0806,0401,0501,0601,0303,0301,0302,0402,0502,0602`
JA4_o (sample)	`t13d3013h2_8d44cdc55eec_5bd17f9d395a`
JA4_ro (sample)	`t13d3013h2_1302,1303,1301,c02c,c030,009f,cca9,cca8,ccaa,c02b,c02f,009e,c024,c028,006b,c023,c027,0067,c00a,c014,0039,c009,c013,0033,009d,009c,003d,003c,0035,002f_ff01,0000,000b,000a,0010,0016,0017,0031,000d,002b,002d,0033,001b_0905,0906,0904,0403,0503,0603,0807,0808,081a,081b,081c,0809,080a,080b,0804,0805,0806,0401,0501,0601,0303,0301,0302,0402,0502,0602`

Co-observed signals

Signals from other families seen in the same observation. A fingerprint spread thinly across many lower-layer signatures is a classic inconsistency signal.

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn020000_5594a17e7e7e_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.18.0, +9 more.The fingerprint page shows the full measured match list. More on the catalog.	735
`ge20nn030000_042112399351_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0.The fingerprint page shows the full measured match list. More on the catalog.	3
`ge20nn030000_ff50983941c1_000000000000_000000000000`	3
`ge20nn030000_e057572924c3_000000000000_000000000000`	3
`ge20nn040000_fc47e34348bb_000000000000_000000000000`	2
`ge20nn020000_e5a56608905c_000000000000_000000000000`	1
`ge20nn030000_65f35519fbff_000000000000_000000000000`	1
`ge20nn10enus_3d89cb764348_000000000000_000000000000`	1
`ge20nr05enus_0297673e9c5b_000000000000_000000000000`	1
`po20nn030000_65f35519fbff_000000000000_000000000000`	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`3:100;4:65536;2:0\|1048510465\|0\|m,s,a,p` Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, curl 8.18.0, curl 8.21.0, +7 more.The fingerprint page shows the full measured match list. More on the catalog.	752

TCP SYN (p0f)

fingerprint	co-occurrences
`4:49+15:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:0`	55
`4:50+14:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:0`	51
`4:52+12:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:0`	46
`4:48+16:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:0`	42
`4:51+13:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:0`	40
`4:50+14:0:1460:65535,4:mss,sok,ts,nop,ws:df,id+:0`	17
`4:53+11:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:0`	15
`4:48+16:0:1460:mss*44,7:mss,sok,ts,nop,ws:df,id+:0`	14
`4:52+12:0:1460:65535,4:mss,sok,ts,nop,ws:df,id+:0`	14
`4:48+16:0:1460:65535,4:mss,sok,ts,nop,ws:df,id+:0`	13

TCP SYN (JA4T)

fingerprint	co-occurrences
`65535_2-4-8-1-3_1460_6`	296
`65535_2-4-8-1-3_1460_4`	77
`64240_2-4-8-1-3_1460_7`	64
`65535_2-4-8-1-3_1460_2`	45
`65535_2-4-8-1-3_1460_8`	33
`65535_2-4-8-1-3_1356_6`	25
`65535_2-4-8-1-3_1432_6`	17
`64800_2-4-8-1-3_1440_7`	13
`65535_2-4-8-1-3_1368_6`	13
`64240_2-4-8-1-3_1412_10`	12

User-Agent

fingerprint	co-occurrences
`curl/8.14.1`	676
`curl/8.21.0`	29
`curl/8.20.0`	23
`curl/8.18.0`	8
`Mozilla/5.0 (compatible; TeardownBriefs/1.0; +https://whop.com/48-hour-teardown)`	3
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:151.0) Gecko/20100101 Firefox/151.0`	2
`FreshRSS/1.28.1 (Linux; https://freshrss.org)`	2
`curl/8.17.0`	2
`get_titles/1.0`	2
`filibot (+https://filibot.com)`	1

Country

fingerprint	co-occurrences
`US` · United States	671
`AE` · United Arab Emirates	11
`ID` · Indonesia	10
`TR` · Turkey	9
`DE` · Germany	8
`CZ` · Czechia	6
`NL` · Netherlands	5
`SE` · Sweden	5
`TH` · Thailand	5
`CA` · Canada	3

Network (ASN)

fingerprint	co-occurrences
`AS7922` · Comcast Cable Communications, LLC	174
`AS20001` · Charter Communications Inc	106
`AS7018` · AT&T Enterprises, LLC	57
`AS20115` · Charter Communications LLC	46
`AS5650` · Verizon Business	43
`AS21928` · T-Mobile USA, Inc.	37
`AS701` · Verizon Business	36
`AS6167` · Verizon Business	20
`AS22773` · Cox Communications Inc.	14
`AS14593` · Space Exploration Technologies Corporation	13