HTTP response header

Policy informing a client how long to cache the HTTPS policy and whether this applies to subdomains.

Header usage statistics

Strict-Transport-Security response header information and usage statistics.

Websites using header Strict-Transport-Security 8,504,071
Percentage of websites that use Strict-Transport-Security header 15.86%
Total discovered header values 4,444
Header uses directives Yes
Header values are unique or random No
Most popular in the country United States of America

Strict-Transport-Security Directives (3 total)

  • includesubdomains
  • max-age
  • preload

Strict-Transport-Security Directives

Strict-Transport-Security directives value information and usage statistics

Directive Share Websites count Unique Values
max-age 36.15% 3,073,977 569
includesubdomains 8.17% 694,761 392
preload 4.40% 374,148 223

Distribution by websites popularity

Strict-Transport-Security detection in the top websites by popularity

Top 10k sites 4,835 websites
Top 100k sites 26,947 websites
Top 1m sites 202,082 websites

Websites utilizing Strict-Transport-Security

List of websites that use Strict-Transport-Security header

Domain Country Rank Contacts United States of America 2 United States of America 2 United States of America 3 United States of America 4 United States of America 4 United States of America 5
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Geographical Distribution

Header usage distribution by websites across the globe.

Common header values

List of top common Strict-Transport-Security header values

Header value Value prevalence
max-age=0 17.85%
max-age=120 17.37%
max-age=31536000 13.53%
max-age=7889238 4.85%
max-age=31536000; includeSubdomains 4.47%
max-age=31536000; includeSubDomains; preload 3.99%
max-age=15768000 3.74%
max-age=604800 2.77%
max-age=31536000; preload 2.72%
max-age=63072000; includeSubDomains 2.35%
max-age=31536000; 2.16%
max-age=300 2.13%
max-age=63072000; includeSubDomains; preload 1.86%
max-age=43200 1.83%
max-age=15552000 1.53%
max-age=63072000 1.51%
max-age=15768000; includeSubDomains 1.11%
max-age=16000000 0.89%
max-age=31556926 0.87%
max-age=63072000; includeSubdomains; 0.68%