Tlsinspect — when does this certificate expire, and what breaks when it does?

Paste a hostname. Tlsinspect opens a TLS connection, reads the certificate chain the server presents, and reports the expiry date, who issued it, every hostname the certificate covers, and whether the chain is complete.

Inspect a certificate Pricing

It is the chain, not just the date

A certificate can be valid and the site still break, because the server sends the leaf without its intermediate. Browsers on desktop paper over it from cache; mobile clients and API consumers do not. That failure is invisible to anyone looking only at the expiry date, and it is the one people lose a weekend to.

What you get

→ Expiry date and days remaining — one glance tells you if it is urgent
→ Issuer name — know who signed it, not just that it exists
→ Subject Alternative Names — every hostname the certificate covers
→ Chain completeness — did the server send the intermediates, or will some clients fail?
→ TLS version and cipher negotiated
→ Full certificate chain, field by field — openssl s_client output without the terminal

Who this is for

Whoever gets the call when the site stops loading. Someone who inherited a server, or runs three of them, and has no idea which certificate expires first. A developer debugging a mobile client that cannot connect while the desktop browser works fine.

Platform note: Hosts behind Cloudflare report as unreachable — the platform cannot open a TCP socket into its own network. This is a platform limitation, not a finding about your server.