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SSL Certificate Checker: is your HTTPS certificate valid?

See when your SSL certificate expires, the names it covers, its chain and TLS version, and your redirects.

  • Free to use
  • Nothing to install
  • No sign-up

How to use the SSL Certificate Checker

Read what the guide says

This is the SSL Certificate Checker.

It shows when your certificate expires, what it covers, and how your addresses redirect.

Public certificates issued from March 2026 last at most 200 days.

So check yours now and then, and make sure it renews by itself.

Type your domain, or any page address on it.

Here, it's a sample domain for a made-up dental clinic.

Then press Check certificate.

The result shows the days left, our checklist's score, and who issued the certificate.

Here, 12 days are left. Our measure: renew within 30 days of the end date.

This box lists what to fix first, with a rough time for each.

Number two: the http:// address reaches https:// through a temporary redirect.

Below, you can see the names it covers, and the chain the server sends.

And here, where each version of your address ends.

Our connection used TLS 1.3, which is current.

No HSTS header here. Add one only once HTTPS works without certificate errors.

Open How to fix to see why it matters and the steps.

Use a permanent 301 redirect instead.

For the redirect, there's an Apache rule ready to copy.

Renew, turn on automatic renewal, then check again to see the new end date.

You can also email yourself a PDF of the result.

Your domain, such as smilestudio.example, or any page address on it. We read the certificate on port 443 and follow the http:// and www. versions.

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About the SSL Certificate Checker

Enter your domain, for example smilestudio.example. We open a secure connection to it on port 443 and read the certificate the server sends: who issued it, when it starts and ends, how many days are left, the names it covers (wildcards included), the chain of certificates, the TLS version and the key. Then we follow the https://, http:// and www. versions of your address to see that they all end on one https:// address, and look for an HSTS header. Each problem comes with the steps to fix it.

How it works

  1. Step 1

    Enter your domain, or any page address on it, such as smilestudio.example.

  2. Step 2

    We connect on port 443, read the certificate and its chain, and follow the https://, http:// and www. versions of the address.

  3. Step 3

    Fix what is flagged, starting with an expired or mismatched certificate, then check that automatic renewal is on.

What a certificate tells you

A certificate names the domains it covers (its subject alternative names), the authority that issued it, and the dates it is valid between. A wildcard such as *.example.com covers one level only: www.example.com, but not example.com itself. Under the CA/Browser Forum rules, public certificates issued from 15 March 2026 last at most 200 days, falling to 100 days in March 2027 and 47 days in March 2029, and Let's Encrypt certificates last 90 days now, so automatic renewal matters.

HTTPS and Google

Google's page experience self-assessment asks whether your pages are served over HTTPS, and Search Console's HTTPS report shows a sample of your pages and how they are served. Google's HTTPS guidance, now on web.dev, says to redirect http:// to https:// with a 301, and to add HSTS only once HTTPS works without certificate errors.

What this tool cannot do

It checks the certificate on port 443 of the domain you enter, from our server, so a CDN or load balancer may show some visitors a different one. It reports the TLS version our connection used, not every version the server accepts, and does not grade ciphers. It does not look for http:// files inside your pages: the On-Page SEO Checker does. Our server's list of trusted authorities is close to, but not the same as, every browser's.

Frequently asked questions

How do I check when my SSL certificate expires?

Enter your domain above: the result shows the end date and the days left, and our measure flags a certificate that ends within 30 days. Let's Encrypt certificates last 90 days now (64 days from 10 February 2027), so check that they renew by themselves. Let's Encrypt advises renewing about two-thirds of the way through a certificate's life.

Why does my certificate not match my domain?

A certificate lists the names it covers, and the address visitors open must be one of them. A common case is a certificate for www.example.com only while visitors open example.com, or the other way round. A wildcard *.example.com does not cover example.com itself. Get one certificate that names both, and redirect one name to the other.

What is a missing intermediate certificate?

Most certificates are issued by an intermediate certificate, which a trusted root certificate issued in turn. The server should send its own certificate and the intermediate. If it sends only its own, the device opening your site has to complete the chain by itself, so our checklist flags it. Install the full chain (often called the CA bundle) that came with your certificate.

Which TLS version should my site use?

TLS 1.2 or TLS 1.3. RFC 8996 deprecated TLS 1.0 and TLS 1.1 in 2021 and says they must not be used. This tool shows the version our connection used. If it shows TLS 1.0 or 1.1, ask your host to turn the old versions off.

Does HTTPS help my Google ranking?

Google announced HTTPS as a ranking signal in 2014, and its page experience self-assessment asks whether pages are served securely, though Google says not every page experience aspect is used directly for ranking. Either way, make https:// your main address, with a 301 redirect from http://.

Related reading

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