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-svc12,617,113
Percentage of websites that use alt-svc header15.39%
Total discovered header values591
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
ma99.89%12,603,05320
quic26.96%3,401,82618
v26.96%3,401,2288
h3-q04626.89%3,393,00311
h3-q04326.89%3,392,73011
h3-250.34%43,0023
clear<0.1%8,6601
persist<0.1%4,6842
h3-24<0.1%4,6532
h2<0.1%2,5818
h3-q048<0.1%852
h3-q049<0.1%842

Connected technologies

Technologies that utilize the header
HTTP/3, category Miscellaneous, total 12,601,699 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=8640054.74%
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"26.32%
h3=":443"; ma=2592000,h3-29=":443"; ma=259200016.50%
h3=":443"; ma=25920000.79%
h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=864000.52%
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=25920000.32%
h3=":443";ma=180;0.07%
clear0.07%
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=":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=":4431"; ma=25920000.04%
h3=":4430"; ma=25920000.04%
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=936000.03%
h3-29=":443"0.03%
quic=":443"; ma=2592000; v="35,39,43,44"0.03%
h3=":443"; ma=86400; persist=10.03%
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%