SSL/TLS Certificate Checker
Check any domain's SSL certificate validity, expiration date, issuer, and HTTPS/HSTS configuration.
Quick Reference & Instructions
Simple steps, pro tips, and execution details
Provide Inputs
Type, paste, or select your values in the form fields below.
Instant Live Analysis
Calculations and formatting happen automatically with zero delay as you type.
Copy or Use Output
Copy results or apply the clean output directly to your projects.
How It Works
Opens a direct TLS connection to the domain to read its certificate (validity window, issuer, subject, alternative names) and checks whether HTTP redirects to HTTPS.
Frequently Asked Questions
Common questions about calculations, assumptions, and edge cases.
It reports what a standard TLS handshake reveals (validity, issuer, SAN) - it does not simulate every browser/OS trust store.
Related Tools
Explore all seo tools →Security Header Checker
Check any public website's HTTP security headers (HSTS, CSP, X-Frame-Options, cookie flags, and more) in seconds.
SEO Audit Tool
Crawl any public page and get a scored, prioritized SEO audit: title/meta, headings, links, images, Open Graph, structured data, and more.