SSL Checker
This free SSL checker connects to a host, reads its SSL certificate and shows whether it is valid, when it expires and who issued it. Enter a hostname to see the expiry date, the certificate chain and the names the certificate covers.
Checked from Germany with a TLS handshake. The checker sends no web request and no other data to the host.
Try an example
How this SSL checker works
The checker opens a TLS connection to the host and port you enter, from our servers in Germany. It reads the certificate that the server presents, validates it against the public root certificates, and reports the dates, issuer, names and chain.
The check runs from one location. If a CDN or a load balancer serves different certificates by region, a visitor elsewhere can see a different result.
How to check SSL certificate expiration
Enter the hostname and read the days remaining and the valid-until date. A result under 30 days turns into a warning. Browsers reject a certificate after its end date, so renew it before that day.
Many certificate authorities support automatic renewal through ACME clients. If you use it, check that the renewal job runs and that the server loads the new certificate.
What an SSL checker result means
- Valid and trusted
- The certificate is inside its validity dates and passed validation against the public root certificates. Check that your hostname is in the names covered.
- Expires soon or expired
- The valid-until date is close or past. Visitors see a browser warning once it has passed.
- Not trusted
- The certificate failed validation. Common causes are a self-signed certificate, a missing intermediate certificate, a certificate issued for another hostname, or an expired certificate. The result shows the reason when it is known.
- Names covered
- The hostnames the certificate is valid for (Subject Alternative Names). A wildcard such as *.example.com covers one level of subdomains, not example.com itself.
- Certificate chain
- The server certificate, then the intermediate certificates that link it to a trusted root. Each row shows the subject, the issuer and the validity dates.
- Protocol and cipher
- The TLS version and cipher suite negotiated in this handshake. TLS 1.0 and 1.1 are deprecated.
SSL certificate checker or SSL monitor: which one do you need
A one-time check shows the state of a certificate today. A certificate fails on a date, and visitors notice before you do. A monitor checks the certificate on a schedule and alerts you before it expires.
Check the SSL certificate of a popular site
Open a ready-made result for a well-known service.
Frequently asked questions
How do I check SSL certificate expiration date?
Enter the hostname above and press Check. The result shows the valid-until date and the days remaining. You can also click the padlock in your browser and open the certificate details. This tool shows the same data without opening the site, and it also works for mail servers on ports 465, 993 and 995.
Why is my certificate chain incomplete or not trusted?
A server should send its own certificate and the intermediate certificates that link it to a trusted root. If the server leaves out an intermediate certificate, some clients cannot build the path to a root and report the certificate as not trusted. Install the full chain on the server (often called the fullchain or bundle file). A self-signed certificate, an expired certificate or a certificate for another hostname also fails validation.
How long are SSL certificates valid?
Browsers and certificate authorities limit how long a certificate may be valid, and the limit has been shrinking. Read the valid-from and valid-until dates of your own certificate and plan renewal around the end date. Automatic renewal removes the manual step.
Which ports can I check?
Port 443 is the default. Under Advanced options you can choose 465, 993, 995 or 8443. These ports use TLS from the first byte. Ports that start in plain text and upgrade later (STARTTLS), such as 25 and 587, are not supported.
Is the result the same from every location?
This tool checks from one location, Germany. Most sites serve the same certificate everywhere. A CDN or a load balancer can serve a different one by region, so test from another network if you suspect that.
Is this SSL checker free?
The tool is free and needs no signup. It limits how fast you can run checks, so wait a few seconds between checks. Continuous monitoring with alerts is a paid Uptrack plan.
Monitor this SSL certificate every minute
Uptrack checks the certificate on a schedule and alerts you before it expires.
Plans from $3/mo, with a 30-day money-back guarantee.