SSL Certificate Checker
Check any domain's SSL certificate: issuer, expiry date, SAN entries, days remaining. Uses the public Certificate Transparency logs via crt.sh, so no server-side TLS handshake is needed.
Technical SEO Intelligence
An expired SSL cert kills traffic for every page on the domain, instantly.
Modern certs auto-renew via Let's Encrypt or your CDN: but auto-renewal breaks silently. Set a reminder to check 30 days out. Enterprises with wildcard certs and multiple SANs often forget a subdomain and let it lapse. This tool shows every subdomain in the cert.
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Next steps
Mixed content kills the padlock even when the cert is good
Pair SSL check with the Mixed Content Checker to catch HTTP resources on HTTPS pages.
Frequently asked questions
What does this tool check?
The SSL certificate for any domain: issuer, validity dates, SAN entries, days to expiry. Via the public Certificate Transparency log.
What is Certificate Transparency?
A public log of every TLS certificate ever issued. Catches rogue cert issuance. The tool uses crt.sh to query it.
What is a SAN?
Subject Alternative Name: additional domains a single cert covers. Check SANs to see every subdomain the cert protects.
How many days before expiry should I renew?
30 days minimum. Many hosts auto-renew at 60 days left. Below 10 is critical.
What is Let's Encrypt?
A free, automated certificate authority. Issues 90-day certs with auto-renewal. Used by most of the modern web.
Is a wildcard cert worth it?
Yes if you have many subdomains.
*.example.com covers any first-level subdomain. Can't cover nested like a.b.example.com.What are CT logs good for beyond cert checks?
Finding subdomains an org forgot to tell you about, catching unauthorised cert issuance, researching competitor infrastructure.
Does the tool detect misconfigured certs?
It reports the latest valid cert on CT. For connection-level issues (chain problems, protocol mismatches) use SSL Labs.
Why isn't my new cert showing up?
CT logs populate within hours of issuance. If a cert was issued but didn't submit to CT (rare), Chrome will reject it.
Can I block certain CAs from issuing certs for my domain?
Yes. Add CAA records (see DNS Lookup tool).
How is this different from browser padlock?
The padlock shows the cert on the live connection. This tool shows all historical certs issued per CT log: useful for audits.
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SEORCE for Chrome, Edge and Firefox
Audits the page you are on: headings, meta tags, schema, indexability, and whether AI crawlers can read it. Export the result as a PDF. Free, with no account.
It audits one page at a time and does not track AI answers. About the extension
Across the whole site
One check here. Every page in SEORCE.
This tool does one job. SEORCE Technical Suite crawls your whole site with fast and secure crawlers and ranks technical issues by impact. AutoFix applies fixes for meta tags, schema, canonical tags, image alt text, headings and internal links for orphan pages on your live site, through one script tag, and the list keeps growing.
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