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SSL Checker

Check any domain's SSL certificate: whether browsers trust it, which domains it covers, who issued it, the TLS version, the full chain and exactly how many days are left before it expires.

Enter a domain or any URL on it. We connect on port 443 and read the certificate.

Reading the certificate…
Connecting securely and checking the certificate chain.
WHY THIS TOOL

What this SSL certificate checker shows

An expired or broken certificate shows visitors a full-page security warning.

Trust Check

Confirms that browsers trust the certificate and that its chain is complete.

Expiry Countdown

Shows the exact expiry date and days left, with a warning under 30 days.

Domains Covered

Lists every domain on the certificate and checks that it covers the one you entered.

Certificate Chain

Shows each certificate in the chain with its issuer and expiry date.

TLS Version

Reports the TLS version and cipher used, and warns about outdated protocols.

HTTPS Redirect

Checks that plain http:// sends visitors to the secure https:// version.

GUIDE

How to use the SSL checker

Catch certificate problems before your visitors see a security warning.

SSL checker showing certificate issuer and days until expiry

Why your SSL certificate matters

An SSL certificate lets browsers open a secure HTTPS connection to your site. When it expires, covers the wrong domain or is installed without its full chain, visitors see a full-page warning instead of your site, and most of them leave. Search engines also prefer secure sites, so a broken certificate can hurt traffic in more than one way.

Using the SSL checker

  1. Enter your domain, with or without https://. Any page URL on the domain works too, and you can check SSL expiry for as many domains as you like.
  2. Click Check SSL. The tool connects to your server on port 443 and reads the certificate directly.
  3. Read the summary: trust, domain match, days left, TLS version and HTTPS redirect.
  4. Look at the details table and the certificate chain if anything is marked red or amber.

What the SSL certificate checker reports

The SSL certificate checker reads the certificate straight from your server, so you see exactly what visitors' browsers see.

  • Trusted or not: whether a normal browser accepts the certificate and its chain.
  • Domains covered: every name on the certificate, and whether the domain you entered is one of them.
  • Issuer: the company that issued the certificate, such as Let's Encrypt or another authority.
  • Validity dates: when the certificate started and when it ends.
  • Key and signature: the key type and size, and the signature method.
  • TLS version: TLS 1.2 or 1.3 is what you want to see.
  • Certificate chain: each certificate from your site up to the authority that issued it.

How to check SSL expiry and avoid surprises

The days left figure is the number to watch. Under 30 days shows a warning and under 14 days is marked as a problem. Free certificates, like the ones from Let's Encrypt, last 90 days and are meant to renew automatically, but renewals can fail quietly after a DNS change, a hosting move or a firewall update. A quick check every few weeks, or after any server change, catches this before visitors do.

Fixing common SSL problems

  • Expired: renew the certificate in your hosting panel and check that auto-renewal is on.
  • Not trusted: reinstall it with the full chain, including the intermediate certificate.
  • Wrong domain: issue a certificate that includes both yoursite.com and www.yoursite.com.
  • Old TLS version: ask your host to enable TLS 1.2 and 1.3 and turn off older versions.
  • No HTTPS redirect: add a 301 redirect from http:// to https://.

Once the certificate is fine, the website security scan checks headers, mixed content and other security settings.

Official reference: web.dev's article on why HTTPS matters explains what visitors lose when a site falls back to plain HTTP.

QUESTIONS

Common questions about the SSL checker

Answers on certificate expiry, covered domains, chain problems and what to do before renewal.

It is a small file on your server that proves your domain's identity and lets browsers create an encrypted HTTPS connection. Without a valid one, browsers show a security warning.

Enter your domain above. The report shows the exact expiry date and how many days are left.

The certificate may be self-signed, expired, issued for a different domain, or installed without its intermediate certificate. Reinstalling the full chain usually fixes the last one.

Yes. Free certificates from Let's Encrypt are trusted by all major browsers. They last 90 days, so auto-renewal must be turned on.

A certificate lists the domains it is valid for. If www.yoursite.com is missing from the list, visitors using the www address will see a warning.

TLS 1.2 and TLS 1.3. Older versions like TLS 1.0 and 1.1 are outdated and blocked by modern browsers.

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