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
55984 8.24% 24811847864 53.18%
2 613107 90.23% 12105241299 25.94%
3 h2
h2-16
h2-15
h2-14
spdy/3.1
spdy/3
http/1.1
268 0.04% 5285295267 11.33%
4 http/1.1
5038 0.74% 3133169309 6.71%
5 spdy/3.1
spdy/3
http/1.1
130 0.02% 607628097 1.30%
6 h2
h2-fb
http/1.1
36 0.01% 367077472 0.79%
7 h2
spdy/3.1
http/1.1
738 0.11% 117364737 0.25%
8 grpc-exp
h2
70 0.01% 97605717 0.21%
9 h2
325 0.05% 75601887 0.16%
10 spdy/3
http/1.1
382 0.06% 11381773 0.02%
11 apns-security-v3
apns-pack-v1
13 0.00% 9978997 0.02%
12 http/1.1
spdy/3.1
h2-14
h2
111 0.02% 5361942 0.01%
13 h2
h2-fb
10 0.00% 4743402 0.01%
14 h2
h2-16
h2-15
h2-14
http/1.1
22 0.00% 3521930 0.01%
15 h2-16
h2-15
h2-14
h2
spdy/3.1
http/1.1
96 0.01% 3306515 0.01%
16 http/1.1
http/1.0
53 0.01% 3149152 0.01%
17 http/1.1
spdy/3.1
h2
92 0.01% 2410172 0.01%
18 http/1.1
spdy/3.1
147 0.02% 1827574 0.00%
19 h2
spdy/3.1
ahfs/1.0
http/1.1
4 0.00% 1434569 0.00%
20 http/1.1
h2
180 0.03% 1332024 0.00%

Selected ALPNs (Server Hello)

Rank ALPN Fingerprints % Fingerprints Connections % Connections
1 689031 76.74% 23964349866 69.98%
2 h2 97945 10.91% 5481120400 16.01%
3 http/1.1 109595 12.21% 4731326875 13.82%
4 grpc-exp 116 0.01% 53435199 0.16%
5 apns-pack-v1:4096:4096 15 0.00% 8455301 0.02%
6 spdy/3.1 1007 0.11% 3602858 0.01%
7 http/1.1 4 0.00% 265678 0.00%
8 h2-fb 7 0.00% 15515 0.00%
9 x-amzn-mqtt-ca 9 0.00% 14703 0.00%
10 bep-relay 15 0.00% 13605 0.00%
11 http/1.0 15 0.00% 2230 0.00%
12 fbvp 12 0.00% 1692 0.00%
13 h2 2 0.00% 1664 0.00%
14 rtmp 5 0.00% 1164 0.00%
15 h2-14 71 0.01% 1101 0.00%
16 spdy/3 26 0.00% 290 0.00%
17 bep/1.0 8 0.00% 85 0.00%
18 ncp 5 0.00% 69 0.00%
19 h2-16 8 0.00% 24 0.00%
20 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 64560 9.50% 34365083116 73.65%
2 h2 58601 8.62% 30779672125 65.97%
3 spdy/3.1 2757 0.41% 6032136763 12.93%
4 spdy/3 1600 0.24% 5908927331 12.66%
5 h2-14 814 0.12% 5300767688 11.36%
6 h2-16 590 0.09% 5292442754 11.34%
7 h2-15 548 0.08% 5292313015 11.34%
8 h2-fb 190 0.03% 372281286 0.80%
9 grpc-exp 109 0.02% 97612701 0.21%
10 apns-security-v3 14 0.00% 10185237 0.02%
11 apns-pack-v1 14 0.00% 10092964 0.02%
12 http/1.0 127 0.02% 3833255 0.01%
13 ahfs/1.0 10 0.00% 2311814 0.00%
14 spdy/2 571 0.08% 1116193 0.00%
15 apns-security-v2 3 0.00% 723896 0.00%
16 spdy/1 465 0.07% 719328 0.00%
17 h2c 75 0.01% 708636 0.00%
18 http/0.9 54 0.01% 675088 0.00%
19 hq 45 0.01% 674650 0.00%
20 x-amzn-mqtt-ca 12 0.00% 128220 0.00%