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
76301 9.51% 28957383497 54.89%
2 715246 89.11% 13251132333 25.12%
3 h2
h2-16
h2-15
h2-14
spdy/3.1
spdy/3
http/1.1
271 0.03% 5361894836 10.16%
4 http/1.1
5382 0.67% 3792089505 7.19%
5 spdy/3.1
spdy/3
http/1.1
134 0.02% 620002814 1.18%
6 h2
h2-fb
http/1.1
36 0.00% 385830734 0.73%
7 h2
spdy/3.1
http/1.1
746 0.09% 125598228 0.24%
8 grpc-exp
h2
72 0.01% 117709030 0.22%
9 h2
347 0.04% 85430067 0.16%
10 spdy/3
http/1.1
391 0.05% 11545903 0.02%
11 apns-security-v3
apns-pack-v1
13 0.00% 10270376 0.02%
12 http/1.1
spdy/3.1
h2-14
h2
111 0.01% 5547704 0.01%
13 h2
h2-fb
10 0.00% 4930196 0.01%
14 http/1.1
http/1.0
56 0.01% 3561403 0.01%
15 h2
h2-16
h2-15
h2-14
http/1.1
22 0.00% 3537488 0.01%
16 h2-16
h2-15
h2-14
h2
spdy/3.1
http/1.1
99 0.01% 3361076 0.01%
17 http/1.1
spdy/3.1
h2
94 0.01% 2453043 0.00%
18 http/1.1
spdy/3.1
147 0.02% 1959600 0.00%
19 http/1.1
h2
187 0.02% 1636905 0.00%
20 h2
spdy/3.1
ahfs/1.0
http/1.1
4 0.00% 1525824 0.00%

Selected ALPNs (Server Hello)

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 764033 76.56% 27837665336 71.41%
2 h2 117370 11.76% 5885086236 15.10%
3 http/1.1 115214 11.55% 5193803275 13.32%
4 grpc-exp 116 0.01% 54689058 0.14%
5 apns-pack-v1:4096:4096 15 0.00% 8561918 0.02%
6 spdy/3.1 1012 0.10% 3606620 0.01%
7 http/1.1 5 0.00% 290644 0.00%
8 x-amzn-mqtt-ca 10 0.00% 29367 0.00%
9 h2-fb 7 0.00% 15515 0.00%
10 bep-relay 15 0.00% 13829 0.00%
11 h2 2 0.00% 2848 0.00%
12 http/1.0 16 0.00% 2327 0.00%
13 fbvp 12 0.00% 1875 0.00%
14 rtmp 5 0.00% 1164 0.00%
15 h2-14 72 0.01% 1120 0.00%
16 spdy/3 26 0.00% 290 0.00%
17 ncp 5 0.00% 94 0.00%
18 bep/1.0 8 0.00% 85 0.00%
19 x-amzn-http-ca 1 0.00% 33 0.00%
20 h2-16 8 0.00% 24 0.00%
21 http/1.1\x00 1 0.00% 1 0.00%

Popular ALPNs supported by clients

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 http/1.1 85362 10.64% 39288011874 74.47%
2 h2 79093 9.85% 35060482357 66.45%
3 spdy/3.1 2843 0.35% 6130054766 11.62%
4 spdy/3 1702 0.21% 5999204854 11.37%
5 h2-14 821 0.10% 5377732532 10.19%
6 h2-16 596 0.07% 5369114991 10.18%
7 h2-15 554 0.07% 5368987072 10.18%
8 h2-fb 195 0.02% 391224727 0.74%
9 grpc-exp 112 0.01% 117716351 0.22%
10 apns-security-v3 14 0.00% 10489089 0.02%
11 apns-pack-v1 14 0.00% 10385200 0.02%
12 http/1.0 153 0.02% 5301171 0.01%
13 ahfs/1.0 11 0.00% 2459758 0.00%
14 spdy/2 652 0.08% 2184156 0.00%
15 spdy/1 547 0.07% 1776694 0.00%
16 h2c 97 0.01% 1763212 0.00%
17 http/0.9 72 0.01% 1729539 0.00%
18 hq 58 0.01% 1729066 0.00%
19 apns-security-v2 3 0.00% 742114 0.00%
20 x-amzn-mqtt-ca 12 0.00% 143489 0.00%