Free website tool

Free SSL Certificate Checker

Is your website SSL certificate valid? Check SSL/TLS certificate details including issuer, expiry date, key size, protocol version, and certificate chain. Detect expired, misconfigured, or self-signed certificates that cause browser security warnings and hurt SEO rankings.

Security

Methodology

1Connects to the target domain over HTTPS and retrieves the full TLS certificate chain from the server handshake.
2Validates the certificate issuer, expiry date, key size (RSA 2048+ or ECDSA P-256+), protocol version (TLS 1.2/1.3), and Subject Alternative Names (SANs).
3Detects expired, self-signed, revoked, and wildcard certificate issues that trigger browser security warnings.

Next steps

What to do with your results

→If expired: renew immediately through your CA or enable auto-renewal (Let's Encrypt, Cloudflare, AWS ACM).
→If self-signed: replace with a certificate from a trusted Certificate Authority — free options include Let's Encrypt.
→Upgrade from TLS 1.0/1.1 to TLS 1.2 or 1.3 — older protocols are deprecated and insecure.
→Enable HSTS (Strict-Transport-Security) header to force all connections over HTTPS.
→Set up certificate transparency monitoring to detect unauthorized certificates for your domain.

Learn more

Frequently asked questions

SSL Certificate Checker — Common questions

Is the SSL Certificate Checker on CheckWebs really free?+

Yes — the SSL Certificate Checker is 100% free with no signup, no account, and no usage limits. Just enter a URL and get instant results.

How accurate is the SSL Certificate Checker?+

Our SSL Certificate Checker runs live checks against the target website in real time. Results reflect the current state of the site at the moment you run the check — not cached or historical data.

What happens if my SSL certificate expires?+

Browsers will show a "Not Secure" warning, which immediately destroys user trust and hurts SEO rankings. Google considers HTTPS a ranking signal.

How early should I renew my SSL certificate?+

Most CAs recommend renewing 30 days before expiry. Our checker flags certificates expiring within 30 days as a warning.

Does this check detect mixed content issues?+

This tool focuses on certificate validity. Use our dedicated Mixed Content Scanner to find insecure HTTP resources on HTTPS pages.

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Home/Tools/Security/SSL

Free website tool

Free SSL Certificate Checker

Security

Methodology

1Connects to the target domain over HTTPS and retrieves the full TLS certificate chain from the server handshake.
2Validates the certificate issuer, expiry date, key size (RSA 2048+ or ECDSA P-256+), protocol version (TLS 1.2/1.3), and Subject Alternative Names (SANs).
3Detects expired, self-signed, revoked, and wildcard certificate issues that trigger browser security warnings.

Next steps

What to do with your results

→If expired: renew immediately through your CA or enable auto-renewal (Let's Encrypt, Cloudflare, AWS ACM).
→If self-signed: replace with a certificate from a trusted Certificate Authority — free options include Let's Encrypt.
→Upgrade from TLS 1.0/1.1 to TLS 1.2 or 1.3 — older protocols are deprecated and insecure.
→Enable HSTS (Strict-Transport-Security) header to force all connections over HTTPS.
→Set up certificate transparency monitoring to detect unauthorized certificates for your domain.

Learn more

Frequently asked questions

SSL Certificate Checker — Common questions

Is the SSL Certificate Checker on CheckWebs really free?+

Yes — the SSL Certificate Checker is 100% free with no signup, no account, and no usage limits. Just enter a URL and get instant results.

How accurate is the SSL Certificate Checker?+

Our SSL Certificate Checker runs live checks against the target website in real time. Results reflect the current state of the site at the moment you run the check — not cached or historical data.

What happens if my SSL certificate expires?+

Browsers will show a "Not Secure" warning, which immediately destroys user trust and hurts SEO rankings. Google considers HTTPS a ranking signal.

How early should I renew my SSL certificate?+

Most CAs recommend renewing 30 days before expiry. Our checker flags certificates expiring within 30 days as a warning.

Does this check detect mixed content issues?+

This tool focuses on certificate validity. Use our dedicated Mixed Content Scanner to find insecure HTTP resources on HTTPS pages.

Free SSL Certificate Checker

Methodology

What to do with your results

Related guides

SSL Certificate Checker — Common questions

Free SSL Certificate Checker

Methodology

What to do with your results

Related guides

SSL Certificate Checker — Common questions