SSL Certificate Checker
Instantly verify the SSL certificate of any website. Check validity, expiry date, issuer, TLS version, and get a security grade — essential for SEO and user trust.
How to Use the SSL Checker
Enter any domain or URL (e.g. example.com or https://example.com) and click Check SSL. The tool connects directly to the server on port 443, reads the TLS certificate, and returns the full analysis in seconds.
SSL Grade Reference
| Grade | Criteria | Action |
|---|---|---|
| A | Valid + TLS 1.3 + 60+ days remaining | No action needed |
| B | Valid + any TLS + 30+ days remaining | Consider upgrading to TLS 1.3 |
| C | Valid but expires in < 30 days | Renew certificate immediately |
| F | Invalid, expired, or untrusted | Fix SSL immediately — affects rankings |
Why SSL Matters for SEO
Google confirmed HTTPS as a ranking signal in 2014 and has progressively strengthened this over time. Since 2018, Chrome labels all HTTP pages as “Not Secure”, which increases bounce rates and destroys user trust. An expired or invalid SSL certificate will result in a browser security warning that stops most visitors from accessing your site entirely.
Beyond rankings, SSL affects Core Web Vitals indirectly — a TLS 1.3 connection completes the handshake in one round-trip instead of two, reducing TTFB (Time to First Byte) and improving your PageSpeed score.
What to Do If Your SSL Has Issues
Certificate Expired
Renew immediately through your hosting provider or certificate authority. If using Let's Encrypt, run certbot renew. Most providers auto-renew with minimal setup.
Certificate Not Trusted
Ensure your certificate chain is complete — intermediate certificates must be installed. Use an SSL validation tool or contact your CA for the correct bundle.
Wrong Domain (SAN Mismatch)
Your certificate does not cover the domain being accessed. Re-issue the certificate with the correct domains listed as SANs, including both www and non-www variants.
Expiring Soon (< 30 days)
Renew before expiry. Most CAs allow renewal 30-90 days early. Set up expiry monitoring or enable auto-renewal to prevent future lapses.
Frequently Asked Questions
What is an SSL certificate and why does my website need one?
An SSL (Secure Sockets Layer) certificate is a digital certificate that authenticates a website's identity and enables an encrypted HTTPS connection. When a website has SSL, data transmitted between the browser and server is encrypted and cannot be intercepted. Google has marked HTTP sites as 'Not Secure' since 2018 and uses HTTPS as a ranking signal, so an SSL certificate is essential for both user trust and SEO.
How long does an SSL certificate last?
As of September 2020, SSL/TLS certificates have a maximum validity of 397 days (approximately 13 months). Before this, certificates could be issued for up to 2 years. Most certificate authorities issue 1-year certificates by default. Some hosting providers offer auto-renewal through Let's Encrypt, which issues 90-day certificates that renew automatically.
What is the difference between TLS 1.2 and TLS 1.3?
TLS 1.3 (released 2018) is significantly faster and more secure than TLS 1.2. TLS 1.3 reduces the handshake from 2 round trips to 1, enables 0-RTT resumption for returning visitors, and removes legacy cryptographic algorithms that were vulnerable to attacks. Modern browsers and servers should use TLS 1.3. If your server still only supports TLS 1.2, upgrading is recommended for both performance and security.
What does the SSL grade mean?
Our SSL grade is calculated based on certificate validity, TLS protocol version, and days remaining. Grade A: valid certificate, TLS 1.3, more than 60 days remaining — excellent security. Grade B: valid certificate, any TLS version, more than 30 days remaining — good. Grade C: valid certificate but less than 30 days remaining or uses older TLS — renewal recommended. Grade F: certificate is invalid, expired, or not trusted.
What are Subject Alternative Names (SANs)?
Subject Alternative Names (SANs) are additional domain names or IP addresses that are protected by a single SSL certificate. For example, a certificate might cover 'example.com', 'www.example.com', 'blog.example.com', and 'shop.example.com' — all listed as SANs. Wildcard certificates use '*' to cover all subdomains of a domain (e.g. '*.example.com'). Multi-domain or SAN certificates are common for websites with multiple subdomains or domain variations.
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