Compare software

CheckTLS vs Internet.nl: catalog facts
CheckTLS	Internet.nl
Freemium Basic tests are available to visitors; batch, monitoring and other features need a paid…	Free Free to use online.
Web	Web, Self-hosted
Shows the full SMTP conversation step by step Tests TLS without sending a real email	Tests website, email and connection setup in one place Covers IPv6, DNSSEC, TLS, DMARC, DANE and RPKI
Cluttered interface with many menus Advanced features require a subscription	Checks standards compliance rather than site speed or content The score reflects the project's own weighting of standards
Web application, Hosted service	Web application, Self-hosted
Closed source	Closed source
License not stated	License not stated
No account needed	Not stated if an account is needed
Needs internet	Needs internet
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.