alt-svc

HTTP response header

The Alt-Svc header is used to list alternate ways to reach this website

Header usage statistics

alt-svc response header information and usage statistics.
Websites using header alt-svc12,515,858
Percentage of websites that use alt-svc header15.49%
Total discovered header values593
Header uses directivesYes
Header values are unique or randomNo
Most popular in the country United States

alt-svc directives (12 total)

  • clear
  • h2
  • h3-24
  • h3-25
  • h3-q043
  • h3-q046
  • h3-q048
  • h3-q049
  • ma
  • persist
  • quic
  • v

alt-svc Directives

alt-svc directives value information and usage statistics
DirectiveShareWebsites countUnique Values
ma99.92%12,506,43521
quic26.78%3,351,51118
v26.77%3,350,8728
h3-q04626.71%3,343,32111
h3-q04326.71%3,343,04911
h3-250.31%39,2873
clear<0.1%7,4121
persist<0.1%4,8802
h3-24<0.1%4,2452
h2<0.1%2,0778
h3-q048<0.1%1062
h3-q049<0.1%1052

Connected technologies

Technologies that utilize the header
HTTP/3, category Miscellaneous, total 12,502,718 websites

alt-svc header usage distribution by website rank



Geographical Distribution

Header usage distribution by websites across the globe.



Websites utilizing alt-svc

List of websites that use alt-svc header
DomainCountryRankContacts
fonts.googleapis.com United States1
facebook.com United States2
www.facebook.com United States2
google.com United States3
www.google.com United States3
wordpress.org United States4
See full domain list

Common header values

List of top common alt-svc header values
Header valueValue prevalence
h3=":443"; ma=8640055.10%
h3=":443"; ma=2592000, h3-29=":443"; ma=2592000, h3-Q050=":443"; ma=2592000, h3-Q046=":443"; ma=2592000, h3-Q043=":443"; ma=2592000, quic=":443"; ma=2592000; v="43,46"26.17%
h3=":443"; ma=2592000,h3-29=":443"; ma=259200016.23%
h3=":443"; ma=25920000.92%
h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=864000.50%
quic=":443"; ma=2592000; v="43,46", h3-Q043=":443"; ma=2592000, h3-Q046=":443"; ma=2592000, h3-Q050=":443"; ma=2592000, h3-25=":443"; ma=2592000, h3-27=":443"; ma=25920000.29%
h3=":443";ma=180;0.08%
clear0.06%
h3=":3443"; ma=2592000, h3-29=":3443"; ma=2592000, h3-Q050=":3443"; ma=2592000, h3-Q046=":3443"; ma=2592000, h3-Q043=":3443"; ma=2592000, quic=":3443"; ma=2592000; v="43,46"0.05%
h3=":443"; ma=2592000, h3-29=":443"; ma=2592000, h3-27=":443"; ma=2592000, h3-Q050=":443"; ma=2592000, h3-Q046=":443"; ma=2592000, h3-Q043=":443"; ma=2592000, h3-Q039=":443"; ma=2592000, quic=":443"; ma=2592000; v="39,43,46"0.05%
h3=":4431"; ma=25920000.04%
h3=":4430"; ma=25920000.04%
h3=":443"; ma=936000.03%
h3-34=":443"; ma=2592000, h3-29=":443"; ma=2592000, h3-27=":443"; ma=2592000, h3-Q050=":443"; ma=2592000, h3-Q046=":443"; ma=2592000, h3-Q043=":443"; ma=2592000, quic=":443"; ma=2592000; v="43,46"0.03%
h3=":443"; ma=86400; persist=10.03%
quic=":443"; ma=2592000; v="35,39,43,44"0.02%
quic=":443"; ma=2592000; v="43,46", h3-Q043=":443"; ma=2592000, h3-Q046=":443"; ma=2592000, h3-Q050=":443"; ma=2592000, h3-24=":443"; ma=2592000, h3-25=":443"; ma=25920000.02%
h3=":444"; ma=2592000, h3-29=":444"; ma=2592000, h3-Q050=":444"; ma=2592000, h3-Q046=":444"; ma=2592000, h3-Q043=":444"; ma=2592000, quic=":444"; ma=2592000; v="43,46"0.02%
quic=":443"; ma=2592000; v="39,43,46", h3-Q039=":443"; ma=2592000, h3-Q043=":443"; ma=2592000, h3-Q046=":443"; ma=2592000, h3-23=":443"; ma=25920000.02%
h3=":443"; ma=86400, h3-29=":443"0.02%