How do I find out when my SSL certificate expires?

Run a detailed request on your https address in the Uptime Monitor. The result shows the issuer, the valid from and valid to dates and the days left.

What happens when an SSL certificate expires?

Browsers show a full-page warning that the connection is not private, many visitors leave, and API clients and webhooks that call the site start to fail with certificate errors.

Does the monitor warn me before the certificate expires?

No. It shows the days left in a detailed request (and saves the date on hourly detailed monitoring), and a daily check fails on the day the certificate has expired. Look at the days left now and then, and set a reminder a few weeks before the end date.

Does this work for any website?

It works for any public https address. Addresses on private networks are blocked on purpose, so a server on your own network cannot be checked.

Guide

How to check when your SSL certificate expires

4 min read · Updated October 26, 2026

An SSL certificate that runs out turns your site into a full-page browser warning for every visitor, usually at the worst moment. The fix takes minutes once you know the date, and finding the date takes one request. This guide shows how to read the expiry date and the days left from a detailed request in the Uptime Monitor, what the certificate errors mean and how to stop being surprised.

Read the expiry date in a minute

The request is made from our server, so you see what an outside visitor gets and not what your own browser has cached.

Add the site as a monitor: sign in, create a monitor with a title and the full address, starting with https.
Run a detailed request on it. A quick request only says whether the site answered; the detailed one also opens the certificate.
Open the SSL part of the result: it shows who issued the certificate, the dates it is valid from and to, the protocol and the number of days left.

What the certificate errors mean

When the certificate is the problem, the check fails and says so in plain words instead of showing a bare timeout.

Expired: the end date has passed. Renew or reissue the certificate, then restart or reload the web server so it serves the new one.
Self-signed: the certificate was made by the server itself and no browser trusts it. Replace it with one from a public authority.
Name does not match: the certificate was issued for a different address, for example for the bare domain but not for www. Reissue it with every name you use.
Cannot be verified: the chain is incomplete, often because the intermediate certificate is missing from the server setup.
Handshake failed: the server and the client could not agree on a protocol or cipher. Check the TLS settings of the server.

Why certificates expire without anyone noticing

Certificates are short on purpose. Many are valid for 90 days and rely on an automatic renewal job. That job fails quietly when a server is moved, a DNS record changes, a firewall blocks the check or the person who set it up leaves. Nothing breaks until the last day, and then everything does.

So the useful habit is to look at the days left now and then, and to watch the site itself so a failed renewal shows up the day it matters.

Keep watching it

Turn on a daily check and the monitor tests the address every day and keeps a 30-day history. A certificate that has expired makes that check fail, so the failure appears in the history on the day it happens. On the Expert and Business plans the hourly check is a detailed one and also saves the certificate expiry date, so you can see it without running anything by hand.

To hear about a failure without opening the page, add a webhook to the monitor: it can post to Discord, Slack, a Google Sheet or a web address of your own when the site goes down and when it comes back. The monitor does not send a countdown warning some weeks before expiry, so check the days left from time to time. If customers use the site, link the monitor to a status page so they see what is going on.

If the page loads but something else looks wrong, the guide Is my website down? explains the status codes and the timing breakdown.

Try it yourself

Start free: new accounts get credits, and the free plan tops them up every week.

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Questions about this guide

How do I find out when my SSL certificate expires?: Run a detailed request on your https address in the Uptime Monitor. The result shows the issuer, the valid from and valid to dates and the days left.
What happens when an SSL certificate expires?: Browsers show a full-page warning that the connection is not private, many visitors leave, and API clients and webhooks that call the site start to fail with certificate errors.
Does the monitor warn me before the certificate expires?: No. It shows the days left in a detailed request (and saves the date on hourly detailed monitoring), and a daily check fails on the day the certificate has expired. Look at the days left now and then, and set a reminder a few weeks before the end date.
Does this work for any website?: It works for any public https address. Addresses on private networks are blocked on purpose, so a server on your own network cannot be checked.