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
6981237 94.39% 10356536965 70.71%
2 195931 2.65% 2074329741 14.16%
3 http/1.1
213351 2.88% 1988914261 13.58%
4 h2
h2-16
h2-15
h2-14
spdy/3.1
spdy/3
http/1.1
140 0.00% 59979699 0.41%
5 grpc-exp
h2
52 0.00% 55537839 0.38%
6 h2
h2-fb
http/1.1
31 0.00% 51621505 0.35%
7 h2
393 0.01% 38137079 0.26%
8 spdy/3.1
spdy/3
http/1.1
55 0.00% 8914105 0.06%
9 h2
spdy/3.1
http/1.1
233 0.00% 4425505 0.03%
10 http/1.1
h2
3763 0.05% 2242973 0.02%
11 http/0.9
http/1.0
http/1.1
spdy/1
spdy/2
spdy/3
h2
h2c
hq
20 0.00% 1190763 0.01%
12 apns-security-v3
apns-pack-v1
15 0.00% 1022531 0.01%
13 http/1.1
http/1.0
16 0.00% 822062 0.01%
14 h2
h2-fb
4 0.00% 610865 0.00%
15 hq
h2c
h2
spdy/3
spdy/2
spdy/1
http/1.1
http/1.0
http/0.9
12 0.00% 582864 0.00%
16 http/0.9
http/1.0
spdy/1
spdy/2
spdy/3
h2c
hq
4 0.00% 239004 0.00%
17 hq
h2c
spdy/3
spdy/2
spdy/1
http/1.0
http/0.9
4 0.00% 237935 0.00%
18 hq
h2c
spdy/3
h2
spdy/2
spdy/1
http/1.1
http/1.0
http/0.9
3 0.00% 131188 0.00%
19 http/1.1
spdy/3.1
60 0.00% 126339 0.00%
20 http/1.1
spdy/3.1
h2-14
h2
35 0.00% 117777 0.00%

Selected ALPNs (Server Hello)

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 5042898 78.96% 8595138532 82.13%
2 h2 718945 11.26% 962669689 9.20%
3 http/1.1 607981 9.52% 903497452 8.63%
4 grpc-exp 26 0.00% 945339 0.01%
5 apns-pack-v1:4096:4096 5 0.00% 88800 0.00%
6 x-amzn-mqtt-ca 22 0.00% 59611 0.00%
7 x-amzn-http-ca 7 0.00% 6487 0.00%
8 http/1.1 4 0.00% 5771 0.00%
9 bep-relay 3 0.00% 1626 0.00%
10 ncp 2 0.00% 1491 0.00%
11 mqtt 2 0.00% 528 0.00%
12 fbvp 4 0.00% 256 0.00%
13 h2 1 0.00% 252 0.00%
14 h2-14 3 0.00% 151 0.00%
15 http/1.0 3 0.00% 110 0.00%
16 spdy/3.1 1 0.00% 9 0.00%

Popular ALPNs supported by clients

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 http/1.1 7199644 97.34% 12476227379 85.18%
2 h2 6986366 94.46% 10571529143 72.18%
3 spdy/3.1 1009 0.01% 73810647 0.50%
4 spdy/3 652 0.01% 71405004 0.49%
5 h2-14 331 0.00% 60182393 0.41%
6 h2-16 240 0.00% 60024628 0.41%
7 h2-15 239 0.00% 60022959 0.41%
8 grpc-exp 85 0.00% 55544931 0.38%
9 h2-fb 93 0.00% 52234459 0.36%
10 http/1.0 103 0.00% 3310328 0.02%
11 spdy/2 346 0.00% 2433725 0.02%
12 spdy/1 271 0.00% 2389778 0.02%
13 h2c 83 0.00% 2387270 0.02%
14 http/0.9 70 0.00% 2386497 0.02%
15 hq 54 0.00% 2381885 0.02%
16 apns-security-v3 16 0.00% 1028216 0.01%
17 apns-pack-v1 16 0.00% 1023325 0.01%
18 quic 29 0.00% 156543 0.00%
19 teleport-reversetunnel 2 0.00% 102069 0.00%
20 x-amzn-mqtt-ca 25 0.00% 66689 0.00%