Troubleshooting "Not Secure" Browser Warnings

Understanding What the Warning Means

A Not Secure warning appears when a browser determines that a connection to your website is not properly encrypted, or that something about your SSL setup does not meet the browser's trust requirements. This warning can appear even on sites with an SSL certificate installed, if the underlying setup has an issue.

Certificate Has Expired

The most common cause of this warning is a certificate that has passed its expiration date. Check your certificate's expiration status directly, and if expired, see SSL Certificate Renewal: Avoiding Expiration Downtime to renew it immediately.

Mixed Content Issues

A frequent cause even on sites with a valid, unexpired certificate is mixed content, meaning your page loads over a secure https connection but pulls in some resources, such as images or scripts, over an insecure http connection. Browsers flag this inconsistency, since the insecure resources undermine the security of the page as a whole. Review your website's code for any hardcoded http links, particularly for images, stylesheets, or scripts, and update them to https.

Domain Mismatch

If your certificate was issued for a specific domain, such as www.yourdomain.com, but visitors are reaching your site through a different variation, such as yourdomain.com without the www, this mismatch can trigger a warning even though a valid certificate exists. Confirm your certificate covers every variation of your domain that visitors might use, or set up a redirect to consistently direct visitors to the exact domain your certificate covers.

Missing Intermediate Certificate

If your certificate was installed without its accompanying intermediate certificate, some browsers may fail to fully trust the certificate chain, even though the primary certificate itself is valid. Revisit Installing an SSL Certificate on cPanel/Plesk to confirm the intermediate certificate was included during installation.

Using an SSL Checker Tool

A free online SSL checker tool can diagnose most of these issues quickly, confirming whether your certificate chain is complete, whether it matches your domain correctly, and whether it is within its valid date range. Running this check is often faster than manually reviewing each possible cause individually.

If the Warning Persists After Fixing the Cause

Some browsers cache security warnings temporarily even after an underlying issue is resolved. If you have addressed the cause but still see the warning, try accessing your site in a private or incognito browser window, or from a different device entirely, to rule out a caching related display issue rather than an ongoing actual problem.