Tool guide
SSL Checker Online
An online SSL checker helps you catch certificate problems before they become browser warnings or broken user journeys.
What The SSL Check Shows
The SSL checker reviews the public certificate for the target host, including issuer, validity dates, and whether the certificate is currently usable.
It is a quick way to spot expired certificates, certificates that are not valid yet, or HTTPS setups that need attention.
When To Run It
Run an SSL check before enabling HSTS, after changing CDNs or hosting providers, and before a certificate renewal window closes.
If users report browser warnings, check SSL first, then inspect redirects to make sure HTTP lands on the intended HTTPS host.
What To Do Next
If the certificate is expired or invalid, renew or replace it at your hosting provider, CDN, or certificate manager.
If SSL looks healthy, continue with redirect checks and security header checks so HTTPS enforcement is consistent.
Common questions
What does an online SSL checker do?
It connects to a public host and reviews the certificate details that browsers rely on for HTTPS.
Can it renew my certificate?
No. It reports certificate status. Renewal happens through your host, CDN, or certificate provider.
Should I check SSL before HSTS?
Yes. HSTS should only be enabled after HTTPS is working reliably for the host and important subdomains.
Why does SSL work on one host but not another?
Certificates are issued for specific names or wildcard patterns. The www and non-www hosts can behave differently.