Why can I not see the certificate issuer or expiry date?

Cloudflare Workers complete the TLS handshake automatically and do not expose the origin certificate chain. This tool confirms whether HTTPS works and whether the site redirects HTTP to HTTPS, plus key security headers.

What does the HTTP to HTTPS redirect check do?

It requests the site over plain HTTP and checks whether the server responds with a redirect to an https:// URL. A redirect protects visitors from downgrade attacks on public networks.

Which security headers are checked?

Strict-Transport-Security, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy.

Why does my site show as failed?

The most common reasons are an expired or misconfigured certificate, a domain that does not serve HTTPS at all, or a TLS version that the runtime refuses to negotiate.

sigxlabs/Network Tools

SSL Checker

Check the SSL/TLS certificate for any domain. See issuer, validity, and expiry.

ssl checker

ssl certificate checker

ssl expiry checker

certificate checker

Domain name

How to use

1
Enter a domain
Type any domain name like example.com. The protocol and www prefix are removed automatically.
2
Click Check
We attempt an HTTPS request to the domain and check whether HTTP redirects to HTTPS.
3
Review the results
See whether HTTPS is enabled, whether HTTP redirects to HTTPS, and which security headers are present.
4
Read the limitations
The results panel explains what this check can and cannot tell you about the certificate.

FAQ

Related tools

WHOIS Lookup

Look up WHOIS and RDAP information for any domain. See registrar, registration, and expiry dates.

DNS Lookup

Query DNS records for any domain. See A, AAAA, MX, TXT, NS, and CNAME records.

HTTP Headers

Check HTTP response headers for any URL. See security headers and get a quick score.