How to use Check SSL Certificate with OpenSSL
- Give Check SSL Certificate with OpenSSL a PEM certificate to work from.
- Hit Parse certificate and Check SSL Certificate with OpenSSL computes the result client-side.
- Review the subject, issuer, validity dates and expiry shown below.
About this tool
Everything Check SSL Certificate with OpenSSL does happens on your own device. Check SSL Certificate with OpenSSL decodes a pasted PEM certificate by walking its ASN.1/DER structure locally to read subject, issuer, validity window and serial.
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 Check SSL Certificate with OpenSSL do?
Use Check SSL Certificate with OpenSSL to check your input without installing anything; everything happens client-side.
Does Check SSL Certificate with OpenSSL cost anything?
No — Check SSL Certificate with OpenSSL is completely free, with no sign-up and no hidden limits.
Is my input private in Check SSL Certificate with OpenSSL?
Yes — your input never leaves your device; Check SSL Certificate with OpenSSL does all the work in your browser.
How do I inspect a live site's certificate in Check SSL Certificate with OpenSSL?
Export the certificate from your browser's padlock as PEM and paste it into Check SSL Certificate with OpenSSL; it decodes the ASN.1/DER fields entirely on your device.
Can I use Check SSL Certificate with OpenSSL without a connection?
Yes — after the first load Check SSL Certificate with OpenSSL runs entirely offline.