Free SSL Certificate Checker — Check Expiry, Issuer & SANs Online

An expired SSL certificate causes browsers to show terrifying red warning pages, tanks your SEO rankings, and breaks API integrations instantly. Our free SSL certificate checker lets you inspect any domain's certificate — expiry date, issuer, Subject Alternative Names, and validity status — in seconds. No signup required.

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What Is an SSL Certificate?

An SSL/TLS certificate is a digital credential that:

1. Encrypts all data transmitted between a browser and your server (HTTPS)
2. Authenticates your server's identity — proving you are who you claim to be
3. Triggers the padlock icon in browser address bars

Without a valid SSL certificate, modern browsers (Chrome, Firefox, Safari) show a "Your connection is not private" warning that drives away virtually all visitors.

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What Our Free SSL Checker Shows

When you check a domain, you get:

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Why SSL Certificates Expire

SSL certificates have a validity period set by the CA/Browser Forum. Since March 15, 2026, the maximum validity dropped from 398 days to 200 days under Ballot SC-081v3, approved unanimously by all major CAs and browser vendors (Apple, Google, Mozilla, Microsoft). It falls further on a fixed schedule: 100 days from March 2027, and 47 days from March 2029.

Why are they time-limited? If a private key is compromised, shorter validity periods limit how long an attacker can use a fraudulent certificate. The shrinking window also forces every organization off manual renewal — by 2029, a cert only lasts 47 days, so automated renewal (certbot renew or equivalent) stops being optional.

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Common SSL Certificate Problems

1. Certificate Expired

The most common issue. After expiry, browsers reject the site completely. All HTTPS traffic fails.

Fix: Renew immediately. If using Let's Encrypt, automate with certbot renew on a cron job.

2. Certificate Domain Mismatch

The certificate was issued for example.com but you're accessing www.example.com or api.example.com.

Fix: Use a wildcard certificate (*.example.com) or a multi-domain SAN certificate.

3. Incomplete Certificate Chain

The server isn't sending intermediate certificates, causing validation failures in some clients.

Fix: Configure your web server to include the full chain file, not just the end-entity certificate.

4. Self-Signed Certificate

Browsers don't trust self-signed certificates. Fine for development, not for production.

Fix: Use a trusted CA — Let's Encrypt is free and trusted everywhere.

5. Weak Cipher Suite

Older certificates using SHA-1 or certificates with key lengths under 2048 bits may be rejected.

Fix: Reissue with SHA-256 and RSA 2048-bit (or ECDSA P-256) key.

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Free SSL Certificate Authorities

You don't need to pay for SSL. These free CAs are trusted by all major browsers:

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How to Check SSL Certificate Expiry Free

1. Go to SolutionGigs Free SSL Checker
2. Enter any domain (e.g., example.com — no https:// needed)
3. Click Check SSL
4. See expiry, issuer, SANs, and validity status instantly
5. No login, no limits, 100% free

You can also check SSL from the command line:

echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -dates

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Monitoring SSL Certificate Expiry

A single manual check isn't enough — you need ongoing monitoring to prevent surprise expirations. Best practices:

1. Set calendar reminders at 60 and 30 days before expiry
2. Enable auto-renewal for Let's Encrypt with certbot renew in a daily/weekly cron job
3. Use monitoring services — UptimeRobot, StatusCake, and Better Uptime all offer free SSL expiry alerts
4. Check all your domains — don't forget staging, API subdomains, and CDN origins

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What Are Subject Alternative Names (SANs)?

SANs are additional domains and subdomains covered by a single certificate. Modern certificates must use SANs (the CN field alone is no longer sufficient per RFC 2818).

Example: A wildcard cert for *.example.com with SANs might cover:

• www.example.com
• api.example.com
• blog.example.com
• example.com (the root domain, listed explicitly)

Our free SSL checker shows all SANs so you can verify which domains are covered.

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Try the Free SSL Certificate Checker

SolutionGigs Free SSL Checker — check any domain's SSL certificate expiry and details in seconds. No signup, 100% free.

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Frequently Asked Questions

What is an SSL certificate? An SSL/TLS certificate is a digital certificate that authenticates a website's identity and enables HTTPS — encrypting all data between the visitor's browser and the server. Websites without it show 'Not Secure' in Chrome and are penalized by Google.

What happens when an SSL certificate expires? Browsers immediately show a 'Your connection is not private' error, blocking all visitors. Search engines may demote or deindex the site. Email delivery from the domain can also fail. Always renew at least 30 days before expiry.

What are Subject Alternative Names (SANs)? SANs allow a single SSL certificate to cover multiple domain names and subdomains. For example, one certificate can secure example.com, www.example.com, shop.example.com, and blog.example.com simultaneously.

How do I check if my SSL certificate is about to expire? Enter your domain name in our free SSL Certificate Checker — it instantly shows the exact expiry date, days remaining, issuer authority, certificate grade, and all SANs. No login needed.

What is the difference between DV, OV, and EV SSL certificates? DV (Domain Validation) verifies domain ownership only — issued in minutes, cheapest. OV (Organization Validation) verifies the business identity — issued in 1–3 days. EV (Extended Validation) requires full legal verification — shows a green padlock with the company name in older browsers.

Why did SSL certificate validity drop to 200 days in 2026? The CA/Browser Forum's Ballot SC-081v3, approved in April 2025 by Apple, Google, Mozilla, and Microsoft, cut the maximum certificate lifetime from 398 to 200 days starting March 15, 2026. It falls further to 100 days in 2027 and 47 days by 2029, forcing every site to automate renewal instead of relying on manual annual updates.