SSL Certificate Checker
Check SSL certificate details, issuer, expiration date, key size, signature algorithm, and certificate chain for any website. Fast, secure, and completely free.
UNDERSTANDING SSL
Why SSL Certificates Matter
SSL certificates encrypt data, verify website identity, and help visitors trust your website. They also improve security, support HTTPS, and can contribute to better search visibility.
Website Identity & Encryption
An SSL certificate confirms your website's identity and encrypts every connection between your server and visitors. This helps protect passwords, payment details, and other sensitive information.
Better Search Visibility
HTTPS is an important trust signal. Secure websites provide a better user experience and are more likely to meet modern search engine expectations.
User Trust
Visitors are more likely to stay on websites that display a secure HTTPS connection. SSL helps build confidence and reduces browser security warnings.
Secure Data Transmission
SSL encrypts information while it travels between a visitor's browser and your server, helping prevent unauthorized access or tampering during transmission.
SSL Certificate Checker
Enter a domain above to instantly analyze its SSL certificate.
Want a Deeper Understanding of SSL Certificates?
We published a complete step-by-step guide covering how SSL certificates work, how to check SSL validity, certificate expiration dates, HTTPS security, common SSL errors, and how to fix SSL issues for free.
📘 Read Full SSL Certificate Guide →Written by Bhavin Sheth • Founder of AllInOneTools
How It Works
Check any public website's SSL certificate in just four simple steps and instantly receive a complete SSL security report.
🌐 Enter a Domain
Enter a public website domain such as example.com. Do not include https://, http://, or any page URL.
🔍 Click "Check SSL"
Our checker securely connects to the website, validates the SSL/TLS connection, and retrieves publicly available certificate information.
📄 Review the Report
Instantly view certificate status, issuer, expiry date, encryption details, key size, and the complete certificate chain.
🛡️ Take Action
Renew expired certificates, fix SSL configuration issues, and ensure your website remains secure and trusted by visitors.
🔒 SSL Certificate Summary
Example SSL Report
* Example result shown for demonstration purposes only.
SECURITY FIRST
How This SSL Checker Protects You
Our SSL Checker is designed with multiple layers of security to safely retrieve SSL certificate information while protecting our servers from abuse and malicious requests.
SSRF Protection
Before connecting to a website, the tool checks whether the domain resolves to a public IP address. Domains pointing to private or reserved IP addresses (such as localhost or internal servers) are automatically blocked to prevent Server-Side Request Forgery (SSRF) attacks.
DNS Rebinding Protection
The checker first resolves the domain name to its IP address and then connects directly to that IP while securely sending the original domain through SNI (Server Name Indication). This approach helps prevent DNS rebinding attacks.
IPv4 & IPv6 Support
Our checker supports both IPv4 and IPv6 websites. It automatically selects the first safe public IP address available and securely retrieves SSL certificate information from the server.
Rate Limiting
To protect the service from abuse, each IP address is limited to 20 SSL checks per minute. Cloudflare-aware IP detection ensures fair usage while keeping the service fast and reliable for everyone.
Your Privacy Matters
We respect your privacy. This SSL Checker only retrieves publicly available SSL certificate information required to generate your report. No sensitive data is collected or stored.
- ✓ No SSL certificates are stored on our servers.
- ✓ Only publicly available certificate information is retrieved.
- ✓ No account, registration, or login is required.
- ✓ Certificate information is fetched securely in real time whenever you perform a check.
Common SSL Checker Errors
If the SSL Checker cannot retrieve a certificate, the error message below explains the most likely reason and how you can fix it.
Invalid Domain Name
The domain format is invalid or incomplete.
Solution: Enter only the domain name, such as
example.com. Do not include
https://,
http://,
or any page URL.
Domain Could Not Be Resolved
The domain does not resolve to a public IP address.
Solution: Check the spelling of the domain, verify that DNS records exist, and make sure the website is online.
Private or Reserved IP
The domain points to a private or reserved IP address.
Solution: For security reasons, localhost, internal servers, and private network addresses cannot be checked.
Secure Connection Failed
The server did not accept a secure SSL/TLS connection.
Solution: Verify that HTTPS is enabled, an SSL certificate is installed correctly, and port 443 is accessible.
Rate Limit Exceeded
Too many SSL checks were submitted within a short period.
Solution: Please wait about one minute before trying again. Each IP address is limited to 20 requests per minute to ensure fair usage.
SSL Checker FAQs
Find answers to the most common questions about SSL certificates, HTTPS security, and using our free SSL Checker.
Why does this tool link to SSL Labs?
A proper SSL/TLS configuration test is extremely complex and must be performed from a dedicated server. Our SSL Checker retrieves certificate information instantly and links to Qualys SSL Labs for a complete security analysis trusted by professionals worldwide.
What is a good SSL Labs grade?
An "A" or "A+" grade indicates an excellent SSL configuration. A "B" grade is generally acceptable, while a "C" grade or below usually indicates outdated protocols or configuration issues that should be corrected.
My certificate is valid but my site shows "Not Secure". Why?
This usually happens because of mixed content. Your page loads over HTTPS but images, JavaScript, CSS, or other resources are still being loaded over HTTP. Update every resource to HTTPS to resolve the warning.
How do I check if my SSL certificate is expired?
Enter your domain name into our SSL Checker and click "Check SSL". The tool instantly displays the expiry date, remaining validity period, issuer information, and current certificate status.
What is the difference between SSL and TLS?
SSL is the older encryption protocol that has been replaced by TLS. Today, websites use TLS 1.2 or TLS 1.3, although the term "SSL certificate" is still commonly used.
How often should I check my SSL certificate?
Check your SSL certificate at least once a month. If you use Let's Encrypt certificates, monitor them more frequently because they expire every 90 days.
What HTTP security headers should my website have?
Important security headers include HSTS, Content Security Policy (CSP), X-Frame-Options, and X-Content-Type-Options. These headers help protect your website against common security threats.
Does SSL affect my Google rankings?
Yes. Google has confirmed HTTPS as a ranking signal. Websites with valid SSL certificates are generally considered more trustworthy, while expired certificates can negatively affect user experience and SEO.
What is a certificate chain and why does it matter?
A certificate chain connects your SSL certificate to a trusted Root Certificate Authority (CA). If any certificate in the chain is missing or invalid, browsers may display security warnings even when the main certificate is valid.