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.
Websites using header Upgrade | 838,374 |
Percentage of websites that use Upgrade header | 7.81% |
Total discovered header values | 65 |
Header uses directives | No |
Header values are unique or random | No |
Most popular in the country | ![]() |
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Top 10k sites | 265 websites |
Top 100k sites | 7,230 websites |
Top 1m sites | 91,882 websites |
Domain | Country | Rank | Contacts |
---|---|---|---|
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11 | |
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72 | |
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322 | |
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636 | |
|
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901 | |
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901 |
Header value | Value prevalence |
---|---|
h2,h2c | 74.69% |
h2 | 24.46% |
h2c | 0.68% |
h2c,h2 | 0.12% |
h2,http:/1.1 | 0.03% |
h2,HTTP,1.1 | 0.00% |
h2,http1.1 | 0.00% |
h2,hc2 | 0.00% |
http:/1.1 | 0.00% |
h2,http/1/1 | 0.00% |
h2 h2c http/1.1 | 0.00% |
h2,http | 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,h2c,http/1.1​ | 0.00% |
h2,,h2c, | 0.00% |
h2,https/1.1 | 0.00% |