HSTS Preload
HSTS Preload embeds a domain in the browser's built-in HSTS preload list, forcing HTTPS even on the first visit (no prior HSTS header needed).
Purpose
It closes the first-visit SSL-strip window of HSTS, keeping the domain on HTTPS at all times.
Mechanism
The site serves an HSTS header with the preload directive and meets the requirements (HTTPS, includeSubDomains, preload), then submits to the hstspreload.org list; the browser's built-in list enforces HTTPS from the very first visit.
Use cases
- Enforced HTTPS
- SSL strip protection
- Security header preloading
Related tools
HTTP Status Codes
Reference table of common HTTP status codes (1xx-5xx) with names, categories, and descriptions. Free, private, and 100% client-side. TOOL
URL Parser
Parse a URL into its components: protocol, host, path, query, hash, port, username, and password. Free, private, and 100% client-side. TOOL