How to use SSL Checker
- Paste or load a PEM certificate into SSL Checker.
- Click Parse certificate — SSL Checker processes everything on your device.
- Read the subject, issuer, validity dates and expiry that SSL Checker lays out for you.
About this tool
Everything SSL Checker does happens on your own device. Paste a PEM certificate and SSL Checker parses the X.509 fields entirely on your device.
The expiry countdown is computed locally, and nothing about the certificate is transmitted. Your input never leaves the page, and no account or install is required.
Frequently asked questions
What does SSL Checker do?
SSL Checker lets you check your input right in the browser, with the result shown instantly and nothing uploaded.
Do I need an account for SSL Checker?
No — SSL Checker needs no account, sign-up or installation.
Where is my data processed by SSL Checker?
Entirely in your browser — SSL Checker keeps your data on your own machine and sends nothing anywhere.
How do I inspect a live site's certificate in SSL Checker?
Export the certificate from your browser's padlock as PEM and paste it into SSL Checker; it decodes the ASN.1/DER fields entirely on your device.
Can I use SSL Checker without a connection?
Yes — after the first load SSL Checker runs entirely offline.