HSTS adoption

Sending the header is common; committing to the preload list is not.

HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% HSTS adoption: 34.4% 34.4%HSTS adoption344,100 of 1,000,000 websites
HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% HSTS preload directive: 9.4% 9.4%HSTS preload directive93,900 of 1,000,000 websites

Denominator: websites · n = 1,000,000

View as table
MeasureShareSitesn
HSTS adoption34.4%344,1001,000,000
HSTS preload directive9.4%93,9001,000,000

Source: GeoTrust Research — The State of SSL/TLS, October 2026