Compare software

HTTP Observatory vs Web Check: catalog facts
HTTP Observatory	Web Check
Free Free to use on the MDN website.	Free Free and open source.
Web	Web, Self-hosted
Checks CSP, HSTS and other security headers Actionable recommendations tied to MDN documentation	Many checks combined in one report Can be self-hosted with Docker
Focuses on headers and configuration, not full vulnerability scanning Only works for publicly reachable sites	Running it yourself takes some setup Only looks at publicly available information
Web application	Self-hosted
Closed source	Open source
License not stated	License not stated
Not stated if an account is needed	No account needed
Needs internet	Not stated if it works offline
Official website Full listing and sources Checked September 23, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.