Why we built this
An expired SSL certificate takes a site offline faster than almost any other kind of outage. Browsers show scary red warnings, search engines drop you from rankings, and customer trust evaporates in minutes. And yet the most common SSL checker tools are slow, covered in ads, or require you to sign up before they'll tell you something as simple as "this certificate expires next Tuesday."
We built SSL Checker so we could stop reaching for openssl on the command line every time we needed to verify a certificate. It connects to the domain, reads the full certificate chain, checks the expiry date, validates the trust path, and flags common issues like missing intermediate certificates or mismatched hostnames — all in a single view, in seconds, with no signup and no hidden tiers.
Who's behind it
SSL Checker is built and maintained by JWWD, an Australian web development studio that's been shipping production web software since the early 2000s. We've watched more than one site go down over a forgotten cert renewal — this tool exists so that doesn't have to happen to you.
Our other free tools
SSL Checker is one of a small suite of free, no-signup tools we maintain for developers and site owners:
- Site Speed Check — measure page load performance and Core Web Vitals.
- Meta Tag Checker — audit a page's meta tags, Open Graph, and schema.
- Broken Link Finder — crawl a site for dead links and bad redirects.
- DMARC Dashboard — check and monitor your email authentication records.
Get in touch
Got a question, a bug report, or a suggestion for a check we should add? Head to our contact page and send us a message — we read every one.