What is the "Certificate uses SHA-1 signature" check?

P1 · HighSecurity

Certificate uses SHA-1 signature

Certificate signature algorithm uses deprecated SHA-1

Code: ssl_sha1_signature

Why it matters

Certificate signature algorithm uses deprecated SHA-1. Browsers and users expect sites to be secure. Missing protections expose visitors to data theft, phishing, and loss of trust.

Related checks in Security

SSL certificate expired

HTTPS certificate has expired

Certificate expiring soon

Certificate expires in < 7 days

Certificate expiring

Certificate expires in < 30 days

No HTTPS redirect

HTTP does not redirect to HTTPS

Mixed content

HTTPS page loads HTTP resources

Run a free scan to check your site

Get a complete audit in under 2 minutes. No account required.

Start Free Scan