upgrade

HTTP response header

The Upgrade header field is an HTTP header field introduced in HTTP/1.1. In the exchange the client begins by making a cleartext request which is later upgraded to a newer HTTP protocol version or switched to a different protocol.

Header usage statistics

upgrade response header information and usage statistics.
Websites using header upgrade6,881,380
Percentage of websites that use upgrade header8.52%
Total discovered header values134
Header uses directivesNo
Header values are unique or randomNo
Most popular in the country United States

upgrade Directives

upgrade directives value information and usage statistics
DirectiveShareWebsites countUnique Values

Connected technologies

Technologies that utilize the header
HTTP/2, category Miscellaneous, total 6,882,027 websites

upgrade header usage distribution by website rank



Geographical Distribution

Header usage distribution by websites across the globe.



Websites utilizing upgrade

List of websites that use upgrade header
DomainCountryRankContacts
simcast.com Singapore105
caniuse.com United States288
ncbi.nlm.nih.gov United States299
www.ncbi.nlm.nih.gov United States299
serenemedia.co.uk GB530
dg-datenschutz.de Germany570
See full domain list

Common header values

List of top common upgrade header values
Header valueValue prevalence
h2,h2c77.41%
h221.26%
h2c1.07%
h2c,h20.22%
h2,http:/1.10.02%
acme-tls/10.00%
websocket0.00%
h2,h2c,http:/1.10.00%
h2,h2c,http/10.00%
h2,HTTP,1.10.00%
h2,Http/1.10.00%
HTTP/1.10.00%
h2,http/1.00.00%
h2,h2c,HTTP/1.10.00%
TLS/1.2, HTTP/1.10.00%
h2,h2c,h2-140.00%
h2,h2c,http,/,1.10.00%
h2,http1/10.00%
http:/1.10.00%
h2,hc20.00%