Credits and licences

Last updated 2026-10-13

Our own code

The tools and page layouts are written for this site, including the small DER reader that decodes certificates and CSRs.

Third-party material

No third-party code is used. Live lookups use these public services, asked directly by your browser when you press a button: Cloudflare DNS and Google Public DNS (DNS over HTTPS), the other public resolvers named on the propagation page, rdap.org and the registries’ RDAP servers (registration data), and crt.sh (Certificate Transparency search). Each tool page names the standard (RFC or specification) behind every rule it applies.