Application Layer Protocol Negotiation (ALPN)

ALPN provides a way for client's to specify the application protocols they support.

Top Client ALPNs

Rank ALPN Unique Fingerprints % Fingerprints Connections % Connections
1 h2
http/1.1
961 19.01% 26202031 73.27%
2 2744 54.28% 4622809 12.93%
3 http/1.1
874 17.29% 3969658 11.10%
4 h2
h2-16
h2-15
h2-14
spdy/3.1
spdy/3
http/1.1
78 1.54% 506532 1.42%
5 grpc-exp
h2
25 0.49% 190447 0.53%
6 h2
h2-fb
http/1.1
15 0.30% 137614 0.38%
7 spdy/3.1
spdy/3
http/1.1
33 0.65% 59272 0.17%
8 h2
89 1.76% 47100 0.13%
9 h2
spdy/3.1
http/1.1
57 1.13% 14462 0.04%
10 apns-security-v3
apns-pack-v1
9 0.18% 3620 0.01%
11 h2
h2-fb
4 0.08% 1579 0.00%
12 23 0.45% 1151 0.00%
13 http/1.1
h2
22 0.44% 1065 0.00%
14 http/0.9
http/1.0
http/1.1
spdy/1
spdy/2
spdy/3
h2
h2c
hq
10 0.20% 907 0.00%
15 h2
spdy/3.1
ahfs/1.0
http/1.1
2 0.04% 609 0.00%
16 http/1.1
spdy/3.1
16 0.32% 566 0.00%
17 http/1.1
http/1.0
3 0.06% 551 0.00%
18 hq
h2c
h2
spdy/3
spdy/2
spdy/1
http/1.1
http/1.0
http/0.9
6 0.12% 469 0.00%
19 x-amzn-mqtt-ca
10 0.20% 362 0.00%
20 http/1.1
h2
quic
2 0.04% 335 0.00%

Selected ALPNs (Server Hello)

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 14826 56.13% 14449295 78.80%
2 http/1.1 6633 25.11% 2010447 10.96%
3 h2 4902 18.56% 1874228 10.22%
4 grpc-exp 14 0.05% 2345 0.01%
5 apns-pack-v1:4096:4096 5 0.02% 630 0.00%
6 x-amzn-mqtt-ca 8 0.03% 319 0.00%
7 http/1.1 1 0.00% 173 0.00%
8 spdy/3.1 9 0.03% 17 0.00%
9 h2 1 0.00% 8 0.00%
10 ncp 2 0.01% 7 0.00%
11 bep-relay 3 0.01% 5 0.00%

Popular ALPNs supported by clients

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 http/1.1 2131 42.16% 30895125 86.39%
2 h2 1301 25.74% 27103638 75.79%
3 spdy/3.1 224 4.43% 581966 1.63%
4 spdy/3 151 2.99% 567771 1.59%
5 h2-14 96 1.90% 506806 1.42%
6 h2-16 82 1.62% 506542 1.42%
7 h2-15 82 1.62% 506542 1.42%
8 grpc-exp 26 0.51% 190448 0.53%
9 h2-fb 21 0.42% 139199 0.39%
10 apns-security-v3 10 0.20% 3688 0.01%
11 apns-pack-v1 10 0.20% 3624 0.01%
12 http/1.0 28 0.55% 2356 0.01%
13 spdy/2 27 0.53% 1808 0.01%
14 spdy/1 26 0.51% 1806 0.01%
15 h2c 25 0.49% 1805 0.01%
16 hq 24 0.47% 1804 0.01%
17 http/0.9 24 0.47% 1804 0.01%
18 ahfs/1.0 3 0.06% 873 0.00%
19 quic 6 0.12% 396 0.00%
20 x-amzn-mqtt-ca 10 0.20% 362 0.00%