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⚠ Certificate & HTTPS

SSL Certificate Checker

Check your site's TLS/SSL certificate — who issued it, when it expires, and whether HTTPS is enforced. An expired certificate throws browser warnings and turns visitors away instantly.

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What this checks

Using public Certificate Transparency logs and a live request, Nattvakt reports your certificate's issuer and expiry date, warns when it is within two weeks of expiring, and checks that plain HTTP redirects to HTTPS.

Why expiry matters

Certificates are short-lived by design — often 90 days. If auto-renewal fails, the site breaks for every visitor until it is fixed. Nattvakt flags certificates with under 14 days remaining so you can act before it lapses.

HTTPS everywhere

A valid certificate is not enough if visitors can still reach the site over plain HTTP. Redirect all HTTP to HTTPS and add an HSTS header so browsers refuse to connect insecurely.

Frequently asked questions

What is the difference between SSL and TLS?

TLS is the modern protocol; SSL is its deprecated predecessor. The term SSL certificate persists, but today it is really a TLS certificate.

How long are certificates valid?

Publicly trusted certificates are capped at roughly 90 days to 13 months depending on the CA; automated renewal, such as with Let's Encrypt, is standard practice.

Where does the expiry data come from?

From public Certificate Transparency logs (via CertSpotter) plus a live HTTPS request to your domain.

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