Free tools

SSL certificate expiration checker

Enter a domain to see when its SSL certificate expires, who issued it, the full chain, the TLS version, whether http:// redirects to https:// and whether HSTS is on. Certificates are getting shorter: from 15 March 2027 a public certificate can last at most 100 days, and from 15 March 2029 at most 47.

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Enter a domain or any address on it. We connect on port 443 and 80 only; nothing is stored. Up to 20 checks an hour.

What the checker tests

  • Certificate: who issued it, when it expires and how many days are left, how long it lasts in total, which names it covers, and whether browsers trust it (we verify against the standard Mozilla root store bundled with Node.js).
  • Chain: every certificate the server sends, from yours up to the root. A missing intermediate is a common reason a site works on desktop but fails on some phones.
  • TLS version: the protocol the server agreed to. TLS 1.2 and 1.3 are fine; browsers no longer accept 1.0 or 1.1.
  • Redirect: whether http:// sends visitors to https:// with a permanent 301 or 308.
  • HSTS: whether the Strict-Transport-Security header tells browsers to use HTTPS every time, and for how long.

Certificate lifetimes are getting shorter

In April 2025 the CA/Browser Forum, the body of certificate authorities and browser makers that sets the rules for public certificates, passed ballot SC-081v3. It cuts the maximum lifetime of a public TLS certificate in three steps:

Maximum TLS certificate validity under SC-081v3
Certificates issued fromMaximum validity
Before 15 March 2026398 days
15 March 2026200 days
15 March 2027100 days
15 March 202947 days

The schedule is in section 6.3.2 of the TLS Baseline Requirements. If anyone renews a certificate by hand today, that job is about to happen every few weeks, so renewal needs to be automatic. Read what the 2027 certificate changes mean for your site, and why Chrome moving to HTTPS by default makes the http to https redirect matter more.

What it does not test

It checks the certificate on port 443 of the address you enter, not every subdomain or service such as mail. It does not grade cipher suites in depth or test for specific TLS vulnerabilities. For the basics of why HTTPS matters, see HTTP vs HTTPS.

Getting it fixed

Every page we build or fix is tested to WCAG 2.2 AA. If you want a person to check the whole site, see our ADA compliance audit. If you already know what is wrong, our accessibility remediation service fixes it in the code, not with an overlay. For a broader automated scan of one page, use the free accessibility checker.

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FAQ Answers

Frequently asked questions

Enter your domain above and the checker shows the expiry date and the days left. In a browser you can also click the icon to the left of the address bar, open the connection details and view the certificate.

Under CA/Browser Forum ballot SC-081v3, public TLS certificates issued from 15 March 2026 may last at most 200 days, from 15 March 2027 at most 100 days, and from 15 March 2029 at most 47 days.

Browsers show a full-page security warning and most visitors leave. Forms, logins and payments stop working for anyone who does not click through, and some services that connect to your site will refuse outright.

HTTP Strict Transport Security is a response header that tells browsers to use HTTPS for your site every time, for a set period, even if someone types http://. A common setting is max-age=31536000; includeSubDomains, once every subdomain works over HTTPS.

Usually the server is not sending the intermediate certificate. Desktop browsers often fill the gap from a cache; some phones and apps do not. The chain section of the report shows what your server sends.

For encryption, yes. A free Let's Encrypt certificate uses the same encryption as a paid domain-validated one. Paid certificates can add organisation validation, warranties or support, but browsers show the same padlock.

Fixed quote

Get a fixed quote in 24 hours

Free, with no obligation. We reply within 24 hours, Monday to Friday, with a written fixed price or the questions we need answered first.

Accessibility fixes, small site
$500 to $2,000
Small business website
About $2,000
Larger site or redesign
$3,000 to $6,000
Web app MVP
$8,000 to $15,000
  • Fixed price in US dollars, in writing, before work starts
  • Built and fixed to WCAG 2.2 AA, tested by hand
  • Code, content and accounts are yours on final payment

Prefer to talk? Call +1 (365) 440-1786 or email info@fourcents.ca.

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