expect-ct

HTTP response header

The Expect-CT header allows sites to opt in to reporting and/or enforcement of Certificate Transparency requirements which prevents the use of misissued certificates for that site from going unnoticed

Header usage statistics

expect-ct response header information and usage statistics.
Websites using header expect-ct144,536
Percentage of websites that use expect-ct header0.25%
Total discovered header values4,938
Header uses directivesYes
Header values are unique or randomNo
Most popular in the country United States

expect-ct directives (3 total)

  • enforce
  • max-age
  • report-uri

expect-ct Directives

expect-ct directives value information and usage statistics
DirectiveShareWebsites countUnique Values
max-age99.23%143,43046
enforce83.67%120,94027
report-uri8.94%12,921272

Connected technologies

Technologies that utilize the header
Cloudflare, category Content Delivery Networks, total 10,750,397 websites
Replit, category Dev Tools, total 5 websites

Websites utilizing expect-ct

List of websites that use expect-ct header
DomainCountryRankContacts
finance.yahoo.com United States102
idp.ecolint.ch Switzerland120
123.click.com.cn China233
bitly.com United States634
salesforce.com United States761
feedly.com United States1,149
See full domain list

Common header values

List of top common expect-ct header values
Header valueValue prevalence
max-age=86400, enforce38%
max-age=7776000, enforce17%
max-age=08%
enforce, max-age=216005%
max-age=864001%
max-age=5184000, enforce1%
enforce, max-age=3001%
enforce, max-age=36001%
enforce, max-age=432001%
enforce, max-age=864001%
enforce,max-age=25920000%
enforce, max-age=300%
enforce; max-age=2592000;0%
enforce, max-age=86400, report-uri="https://hpage-report.uriports.com/reports/enforce"0%
max-age=77760000%
max-age=3600, enforce0%
enforce; max-age=300%
enforce; max-age=6048000%
enforce, max-age=6048000%
max-age=31536000, enforce0%