CertAvert

CertAvert is a web-based SSL/TLS inspection service built around one core question: is a site’s certificate valid, trusted, and correctly issued for the domain? Instead of installing command-line utilities, users enter a domain and get a readable summary of certificate expiry, issuer, and trust status.

The site extends beyond a single expiry check. Separate tools cover certificate names and SANs, certificate chain construction, supported TLS versions and ciphers, DNS and domain registration lookups, and a decoder for certificates, CSRs, and chains. This makes it useful for diagnosing mismatches, expired intermediates, or incomplete chains.

It is aimed at webmasters, developers, DevOps engineers, and IT administrators who need fast answers during setup, migration, or troubleshooting. Casual users can also confirm whether a site’s HTTPS is properly configured before entering sensitive information.

Use it as a first-pass diagnostic: check the domain, review SAN coverage and chain status, then confirm TLS versions and DNS records if something looks off. For ongoing assurance, pair it with scheduled monitoring rather than relying on one-off checks.

Overall, CertAvert is a focused, no-install toolkit for certificate and TLS hygiene, best suited to users who already know what to look for and want the data quickly.