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Jamsheer Ali
Jamsheer Ali

Posted on • Originally published at dnsfly.net

How to Check SSL Certificates

An expired or misconfigured SSL certificate can take your entire site down with a browser warning. Here's how to check yours — and what to look for.

What is an SSL Certificate?

An SSL certificate is a small data file
that does two things: it encrypts the data between a visitor's browser and your server, and it verifies that your server actually belongs to you.

When a website has a valid SSL certificate, the browser shows a padlock icon and the URL starts with https://. Without one, browsers display warnings that scare visitors away and search engines penalize your rankings.

An SSL certificate contains:

  • Domain name
  • Issuer
  • Validity period
  • Certificate chain
  • Public key

3 Ways to Check an SSL Certificate

  1. DNSFly SSL Checker
  2. Browser padlock
  3. Command line with openssl commands

Common SSL Issues

Certificate expired
Domain name mismatch
Incomplete certificate chain
Mixed content warnings
Self-signed certificate

checkout your SSL for free at DNSFly

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