What is a certificate chain, and why does it matter?

Your certificate is signed by an intermediate, which is signed by a trusted root. Your server must send the leaf AND the intermediate(s) so every visitor can build that path to a root they trust.

Why does my site work in one browser but not another?

Usually a missing intermediate. Some clients cache or fetch it and appear fine, while others fail. Reinstall the full chain bundle (leaf + intermediates) so more browsers and devices accept it.

Is the chain checker free?

Yes, with no signup. SSLCanary can also keep watching the chain and warn you if it breaks — add your sites to a free account.

How do I fix a missing intermediate certificate?

Install the full chain bundle your certificate authority provides — your leaf certificate plus every intermediate — not just the leaf on its own. Most CAs offer a combined "fullchain" file; reinstall it and restart your server.

What is an intermediate certificate, or a certificate chain?

A certificate chain links your website's certificate to a trusted root through one or more intermediate certificates. Roots stay offline for safety, so intermediates do the signing — and your server must send them all.

SSL Chain & Installation Checker

Check whether your certificate is installed with its complete chain — the most common cause of "works for me but not for them" errors.

Type a website above and press Check. You'll get the status and its exact expiry date, with the technical details a step away.

How it works

We fetch the chain

We connect to your site and pull the exact certificate chain your server presents to every visitor, right now.

We check it's complete

We check that the intermediates needed to build a trusted path are present, from your certificate up toward a publicly trusted root.

We confirm or flag

You get a clear yes — the chain is complete and trusted — or the exact gap to fix, like a missing intermediate.

Common questions

What is a certificate chain, and why does it matter?: Your certificate is signed by an intermediate, which is signed by a trusted root. Your server must send the leaf AND the intermediate(s) so every visitor can build that path to a root they trust.
Why does my site work in one browser but not another?: Usually a missing intermediate. Some clients cache or fetch it and appear fine, while others fail. Reinstall the full chain bundle (leaf + intermediates) so more browsers and devices accept it.
Is the chain checker free?: Yes, with no signup. SSLCanary can also keep watching the chain and warn you if it breaks — add your sites to a free account.
How do I fix a missing intermediate certificate?: Install the full chain bundle your certificate authority provides — your leaf certificate plus every intermediate — not just the leaf on its own. Most CAs offer a combined "fullchain" file; reinstall it and restart your server.
What is an intermediate certificate, or a certificate chain?: A certificate chain links your website's certificate to a trusted root through one or more intermediate certificates. Roots stay offline for safety, so intermediates do the signing — and your server must send them all.

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