---
title: "Free SSL Checker Tool"
description: "Check the SSL certificate status of your website. Ensure your site is secure with our free SSL checker."
url: "https://testomato.com/tools/ssl-checker/"
---

# Free SSL Certificate Checker

## Free SSL Checker

Use this free SSL checker tool to **check SSL certificate** details for any domain or hostname. Enter a domain above and the tool will return the certificate details.

## Understanding SSL certificate fields

An SSL (or TLS) certificate is a digital document issued by a Certificate Authority (CA) that binds a public key to a domain name, enabling HTTPS encryption and allowing browsers to verify the identity of a web server. Here are some of the most important fields the SSL Checker returns:

- **Issuer Organization**: The organization behind the issuing CA (e.g. DigiCert or Sectigo).
- **Subject (CN)**: The common name the certificate was issued to, typically the domain name.
- **Subject Alternative Names**: Additional domains or subdomains covered by the same certificate.
- **Issued Date / Expiry Date**: The validity window for the certificate. After the expiry date, browsers will block or warn visitors about your site.
- **Currently Valid**: Whether the certificate is trusted. Revocation or domain mismatch can invalidate a certificate before it expires.

## How to check SSL certificate expiration date

Enter the domain above and the tool will show the exact expiry date and days remaining. A certificate that expires without being renewed will cause browser security warnings and break HTTPS for your visitors.

To get alerts before that happens, [SSL certificate monitoring](https://testomato.com/ssl-monitoring/) in Testomato checks your certificates automatically and notifies you in advance. See how to [configure SSL expiry alerts](https://testomato.com/blog/ssl-certificate-monitoring/) in Testomato.

## Monitor your SSL certificates and website uptime

You can try it all free for 14 days with **no credit card** and **no commitment**.

[Monitor Your SSL Certificate](https://testomato.com/sign-up/ "Monitor Your SSL Certificate")