My name is Lyas Spiehler, and I work as a consultant at Sapphire Health. I developed certificatetools.com because x509 certificates and the surrounding technologies like TLS can be difficult to learn. I wanted a way to quickly learn, test, and explore ideas with certificates. Certificatetools.com is packed with functionality to test your TLS configurations, revocation and generate certificates in a variety of ways. It shows all the OpenSSL commands needed to reproduce the same results securely on local systems for production use. I'm very excited about recently adding support for quantum-ready cryptographic algorithms recently standardized by NIST as we all begin to prepare for the migration to post-quantum cryptography.