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SSL Certificate Checker

Verify the SSL certificate for any domain. Check validity, expiry date, issuer, encryption strength and subject alternative names. Instantly detect expired or misconfigured HTTPS certificates.

Try: google.com  ·  github.com  ·  cloudflare.com  ·  expired.badssl.com
Enter a domain to check its SSL certificate

What Is an SSL Certificate?

An SSL certificate (now more accurately called a TLS certificate) is a digital file that authenticates a website's identity and enables encrypted communication between your browser and the server. When a site has a valid SSL certificate, your browser shows a padlock icon and uses HTTPS instead of HTTP.

SSL certificates are issued by Certificate Authorities (CAs) — trusted organizations that verify the domain owner's identity before issuing a certificate. The certificate contains the domain name, issuer details, validity period and a public key used for encryption.

Expired or misconfigured SSL certificates cause browser security warnings that deter visitors and indicate potential security risks. Website owners should monitor certificate expiry dates and renew at least 30 days before the expiry date to avoid downtime.

SSL Certificate Types

DV — Domain Validated
Verifies only domain ownership. Issued within minutes. Free via Let's Encrypt. Suitable for most websites and blogs. Does not verify organization identity.
OV — Organization Validated
Verifies domain ownership and organization identity. CA checks business registration documents. Takes 1 to 3 days. Used by businesses and government sites.
EV — Extended Validation
The highest validation level. Requires thorough vetting of the organization. Historically showed the company name in the browser bar. Used by banks and large enterprises.
Wildcard
Covers the main domain and all its subdomains with a single certificate (*.example.com). Cost-effective for sites with many subdomains.

Frequently Asked Questions

How often should I check my SSL certificate?
Check your SSL certificate at least monthly, and set up monitoring alerts for 60 days and 30 days before expiry. Many hosting providers offer automatic renewal, but renewal failures are common and can cause unexpected downtime and visitor trust issues.
What happens when an SSL certificate expires?
Browsers display a full-page security warning blocking access to the site. Visitors see messages like "Your connection is not private" and must click through multiple warnings to proceed. This causes significant drops in traffic, trust and conversion rates.
Are free SSL certificates safe?
Yes. Free DV certificates from Let's Encrypt use the same encryption strength as paid certificates. The only difference is validation level — free certificates verify domain ownership but not organization identity. For most websites, a free DV certificate is completely adequate.
What is a wildcard SSL certificate?
A wildcard certificate covers a domain and all of its immediate subdomains using an asterisk notation (*.example.com). This means one certificate covers app.example.com, blog.example.com, mail.example.com and any other subdomain, saving the cost and management overhead of individual certificates.
What are Subject Alternative Names?
Subject Alternative Names (SANs) are additional domain names or subdomains that a certificate is valid for. A single certificate can cover multiple domains using SANs — for example, a certificate might cover example.com and www.example.com and app.example.com simultaneously.
Does HTTPS mean a website is safe?
HTTPS means the connection between your browser and the server is encrypted, not that the website itself is trustworthy. Phishing sites and malware distribution sites routinely use valid SSL certificates. Always verify the domain name carefully regardless of the padlock icon.