SSL Checker

Verify SSL and TLS certificate health for any domain

Focused on accuracy and clear security signals

Type a domain to check SSL and TLS certificate status.

Advertisement
Your ad could be here

Short description

Check a domain SSL and TLS certificate validity, identity, and trust in a single scan. Results are classified as VALID, WARNING, or INVALID so you can act quickly.

What the SSL Checker verifies

Certificate validity window (not expired, not early)
Hostname match against SAN entries
Issuer and trust chain status
Self-signed detection
TLS version and cipher negotiated
Expiry warning threshold (default 30 days)

Example result and how to read it

SSL CHECK RESULT ------------------------------- Status : WARNING Target : example.com:443 Certificate Issuer : Let's Encrypt Subject : example.com Valid From : Tue, 07 Jan 2026 00:00:00 GMT Valid To : Mon, 07 Apr 2026 23:59:59 GMT Days Left : 28 days Connection TLS Version : TLSv1.2 Cipher Suite : TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 Identity Hostname Match: OK SAN (summary) : example.com, www.example.com +2 more Trust Self-signed : NO Trusted Chain : YES Chain Count : 3 Warnings - Certificate expires in 28 days

VALID

Certificate is trusted, matches the domain, and is within the valid window.

WARNING

Certificate works, but attention is required, such as upcoming expiry.

INVALID

Security issue detected, such as expired, mismatch, or untrusted chain.

When to use this tool

  • Before enabling HTTPS on a new domain or subdomain
  • After renewing or replacing certificates
  • When users report browser warnings or blocked pages
  • For periodic checks of expiring certificates

Limitations

  • Results are based on a single connection path and may differ by region.
  • Does not perform full revocation checks (OCSP or CRL).
  • Focuses on certificate health and identity, not a full security grade.

Frequently asked questions

Why does the status show WARNING?

WARNING means the certificate is still valid but needs attention, such as expiring soon or using an older TLS version.

What causes an INVALID status?

INVALID is used when a security issue is detected, such as an expired certificate, hostname mismatch, self-signed certificate, or untrusted chain.

Does this tool perform OCSP or CRL revocation checks?

No. The checker focuses on certificate validity, identity, and trust signals and does not perform full revocation checks.

Why can results differ between networks?

TLS results can vary by region or network due to different routing, caching, or server configurations.

SSL Checker - Verify SSL and TLS Certificate Health | CuscusLab