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 8,390,338
Percentage of websites that use Upgrade header 8.42%
Total discovered header values 133
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 8,390,066 websites

Distribution by websites popularity

Upgrade detection in the top websites by popularity

Top 10k sites 235 websites
Top 100k sites 3,497 websites
Top 1m sites 68,337 websites

Websites utilizing Upgrade

List of websites that use Upgrade header

Domain Country Rank Contacts
gmpg.org Canada 10
simcast.com United States of America 105
caniuse.com United States of America 288
www.ncbi.nlm.nih.gov United States of America 299
homeblogs.space France 657
monicarettig.com France 658
See full domain list
Flat price per the report, subscription is not required.

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 76.02%
h2 20.65%
h2c 3.10%
h2c,h2 0.18%
h2,http:/1.1 0.03%
h2,h2c,http/1 0.00%
h2,HTTP,1.1 0.00%
h2,h2c,http/1.1​ 0.00%
HTTP/1.1 0.00%
h2,h2c,HTTP/1.1 0.00%
h2,hc2 0.00%
h2,Http/1.1 0.00%
h2,http1.1 0.00%
h2,h2c,http:/1.1 0.00%
TLS/1.2, HTTP/1.1 0.00%
http:/1.1 0.00%
h2,h2c,h2-14 0.00%
h2,h2c,h2,h2c 0.00%
TLS/1.0 0.00%
h2,h2c,http/2.4 0.00%