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 Upgrade 5,247,337
Percentage of websites that use Upgrade header 9.78%
Total discovered header values 104
Header uses directives No
Header values are unique or random No
Most popular in the country United States of America

Connected technologies

Technologies that utilize the header

HTTP/2, category Miscellaneous, total 5,247,256 websites

Distribution by websites popularity

Upgrade detection in the top websites by popularity

Top 10k sites 272 websites
Top 100k sites 7,190 websites
Top 1m sites 91,392 websites

Websites utilizing Upgrade

List of websites that use Upgrade header

Domain Country Rank Contacts
gmpg.org Canada 11
searchengineland.com United States of America 322
caniuse.com United States of America 636
vizeo.net France 901
www.vizeo.net France 901
brainoff.com United States of America 934
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Geographical Distribution

Header usage distribution by websites across the globe.

Common header values

List of top common Upgrade header values

Header value Value prevalence
h2,h2c 75.43%
h2 23.19%
h2c 1.17%
h2c,h2 0.17%
h2,http:/1.1 0.03%
h2,HTTP,1.1 0.00%
h2,h2c,http/1 0.00%
h2,h2c,http/1.1​ 0.00%
h2,http1.1 0.00%
HTTP/1.1 0.00%
h2,HTTP/1.1 0.00%
h2,hc2 0.00%
h2,h2c,http:/1.1 0.00%
http:/1.1 0.00%
h2,h2c,HTTP/1.1 0.00%
h2,h2c,h2-14 0.00%
h2,http/1/1 0.00%
h2,http 0.00%
h2,h2c,h2,h2c 0.00%
h2,h2c,# 0.00%