Verify Website SSL Security
An expired or misconfigured SSL certificate will immediately block users from accessing your website, displaying a terrifying "Your connection is not private" browser warning. Our SSL Certificate Checker allows you to query any domain to verify its encryption status and expiration date instantly.
Crucial SSL Diagnostics
Enter a domain name to retrieve a comprehensive security report detailing:
- Validity Period: The exact date and time the certificate was issued and, critically, when it will expire.
- Issuer Details: Verify which Certificate Authority (CA), such as Let's Encrypt, DigiCert, or Cloudflare, signed the certificate.
- SANs (Subject Alternative Names): View all the subdomains (e.g., `www.`, `api.`) that are protected by this specific certificate.
- Encryption Algorithm: Check the public key strength (e.g., RSA 2048-bit or modern ECDSA).
How to Use This Tool
- Upload or Input Data: Select your file or paste your data directly into the tool interface. Everything remains on your device.
- Configure & Process: Adjust any optional settings if necessary. The tool will process your data instantly inside your browser.
- Download Result: Preview the output and click the download or copy button to save your final results.
Frequently Asked Questions
Why is the browser showing an SSL error even though the cert is valid?
This is often caused by 'Mixed Content'. Even if the SSL cert is valid, if your HTTPS page attempts to load images or scripts over an insecure HTTP connection, the browser will flag the site as insecure.
What is the 'Certificate Chain'?
Browsers only trust a small list of Root Authorities. Your server's certificate is usually signed by an 'Intermediate' authority. The chain proves the link from your site up to the trusted Root.
Does this tool check for vulnerabilities like Heartbleed?
This tool focuses on the validity and metadata of the certificate itself. Dedicated vulnerability scanners are required to test the actual server TLS configuration.