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
22674178 35.62% 13699820383 67.02%
2 276823 0.43% 3259245121 15.94%
3 http/1.1
803714 1.26% 3097391972 15.15%
4 grpc-exp
h2
54 0.00% 91528895 0.45%
5 h2
h2-fb
http/1.1
34 0.00% 85209933 0.42%
6 h2
h2-16
h2-15
h2-14
spdy/3.1
spdy/3
http/1.1
153 0.00% 77316136 0.38%
7 h2
445 0.00% 59803563 0.29%
8 39895487 62.67% 39895972 0.20%
9 spdy/3.1
spdy/3
http/1.1
57 0.00% 11780674 0.06%
10 h2
spdy/3.1
http/1.1
258 0.00% 6060354 0.03%
11 http/1.1
h2
4693 0.01% 3457419 0.02%
12 http/0.9
http/1.0
http/1.1
spdy/1
spdy/2
spdy/3
h2
h2c
hq
25 0.00% 1673821 0.01%
13 apns-security-v3
apns-pack-v1
15 0.00% 1581105 0.01%
14 http/1.1
http/1.0
17 0.00% 1223725 0.01%
15 h2
h2-fb
4 0.00% 1061885 0.01%
16 hq
h2c
h2
spdy/3
spdy/2
spdy/1
http/1.1
http/1.0
http/0.9
15 0.00% 839684 0.00%
17 http/1.1
https/1.1
2 0.00% 714606 0.00%
18 http/0.9
http/1.0
spdy/1
spdy/2
spdy/3
h2c
hq
5 0.00% 335872 0.00%
19 hq
h2c
spdy/3
spdy/2
spdy/1
http/1.0
http/0.9
5 0.00% 334574 0.00%
20 h2
http/1.1
http/1.0
17 0.00% 211185 0.00%

Selected ALPNs (Server Hello)

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 5419081 78.83% 8783252108 82.15%
2 h2 783353 11.39% 981480119 9.18%
3 http/1.1 655864 9.54% 923076053 8.63%
4 grpc-exp 26 0.00% 954140 0.01%
5 apns-pack-v1:4096:4096 5 0.00% 90045 0.00%
6 x-amzn-mqtt-ca 23 0.00% 60686 0.00%
7 x-amzn-http-ca 7 0.00% 6578 0.00%
8 http/1.1 4 0.00% 5832 0.00%
9 bep-relay 3 0.00% 1626 0.00%
10 ncp 2 0.00% 1503 0.00%
11 mqtt 2 0.00% 531 0.00%
12 h2 1 0.00% 260 0.00%
13 fbvp 4 0.00% 260 0.00%
14 h2-14 3 0.00% 167 0.00%
15 http/1.0 3 0.00% 124 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 23484163 36.89% 16986868986 83.10%
2 h2 22680437 35.63% 14027731223 68.63%
3 spdy/3.1 1105 0.00% 95794445 0.47%
4 spdy/3 718 0.00% 92605139 0.45%
5 grpc-exp 90 0.00% 91538822 0.45%
6 h2-fb 108 0.00% 86274787 0.42%
7 h2-14 371 0.00% 77583639 0.38%
8 h2-16 271 0.00% 77374190 0.38%
9 h2-15 266 0.00% 77372483 0.38%
10 http/1.0 117 0.00% 4790528 0.02%
11 spdy/2 418 0.00% 3414934 0.02%
12 spdy/1 299 0.00% 3358830 0.02%
13 h2c 97 0.00% 3355261 0.02%
14 http/0.9 83 0.00% 3354692 0.02%
15 hq 64 0.00% 3347876 0.02%
16 apns-security-v3 16 0.00% 1589157 0.01%
17 apns-pack-v1 16 0.00% 1581919 0.01%
18 https/1.1 2 0.00% 714606 0.00%
19 quic 32 0.00% 219120 0.00%
20 x-amzn-mqtt-ca 30 0.00% 133499 0.00%