SSL Certificate Checker
Check if a website's SSL certificate is valid, trusted and when it expires. Also see the issuer, covered domains, TLS version, HTTPS redirect and HSTS.
Checked from our server in a few seconds. We don't store the sites you check.
How to Check an SSL Certificate
Three steps to a full SSL report.
Enter the Domain
Type the website, like example.com — https:// is optional.
Click Check SSL
We connect securely on port 443 and read the certificate the server sends.
Review the Report
See days left, expiry date, issuer, trust status, TLS versions and any problems to fix.
Shows
Expiry & days left
Checks
Chain, name, TLS
Also
HTTPS redirect & HSTS
Sign-up
Not needed
Works on
Phone & computer
Price
100% free
Common SSL Errors and Fixes
What each problem means and how to fix it.
| Problem | What it means | How to fix |
|---|---|---|
| Expired | The certificate's end date has passed | Renew it (Let's Encrypt renews automatically every 60–90 days) |
| Name mismatch | The certificate is for a different domain | Issue a certificate that includes this domain (and www) |
| Incomplete chain | The intermediate certificate is missing | Install the full chain (fullchain.pem) on the server |
| Self-signed | Not issued by a trusted authority | Use a free certificate from Let's Encrypt or your host |
| Old TLS 1.0 / 1.1 | Outdated, insecure protocols are enabled | Allow only TLS 1.2 and TLS 1.3 |
| No HTTPS redirect | Visitors can still open the http:// version | Add a 301 redirect from http:// to https:// |
| No HSTS | Browsers aren't told to always use HTTPS | Add the Strict-Transport-Security header |
What Can You Use It For?
Popular ways people use SSL Checker.
Avoid Expiry Surprises
See exactly how many days are left before your certificate expires.
Fix Browser Warnings
Find out why visitors see "Your connection is not private".
After a Migration
Confirm SSL is installed correctly after moving hosts or CDNs.
Check Any Site
Verify a shop or service is using a valid, trusted certificate.
Tips for the Best Result
- Free Let's Encrypt certificates last 90 days — make sure auto-renewal is on.
- Cover both example.com and www.example.com in your certificate.
- Redirect all http:// traffic to https:// — our Htaccess Redirect Generator writes the rules for you.
- From 2026 the maximum certificate lifetime is getting shorter, so automatic renewal matters more than ever.
Frequently Asked Questions
Quick answers about SSL Checker.
Enter the domain and click Check SSL. You'll see if the certificate is trusted, matches the domain and is not expired, plus the exact expiry date.
The report shows the expiry date and the number of days left. Renew before it reaches zero to avoid browser warnings.
The server is not sending the intermediate certificate. Some browsers and apps then can't verify it. Install the full chain file on your server.
The certificate was issued for a different domain name. Make sure it lists the exact domain visitors use, including www if needed.
They are the secure protocols used by HTTPS. TLS 1.3 is the newest and fastest. Older TLS 1.0 and 1.1 should be turned off.
HTTP Strict Transport Security tells browsers to always use HTTPS for your site, which protects visitors from downgrade attacks.
This tool checks the standard HTTPS port 443, which is used by websites.
Yes — 100% free, with no sign-up. There is a fair daily limit per visitor to keep the service fast for everyone.
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