How to use Check SSL Certificate (OpenSSL)
- Add a PEM certificate to Check SSL Certificate (OpenSSL) to get started.
- Press Parse certificate to run it locally in your browser.
- Review the subject, issuer, validity dates and expiry shown below.
About this tool
Check SSL Certificate (OpenSSL) is a static, client-side tool with no backend. Check SSL Certificate (OpenSSL) decodes a pasted PEM certificate by walking its ASN.1/DER structure locally to read subject, issuer, validity window and serial.
To check a live site, export its certificate from the browser padlock as PEM and paste it here. Your input never leaves the page, and no account or install is required.
Frequently asked questions
What does Check SSL Certificate (OpenSSL) do?
Use Check SSL Certificate (OpenSSL) to check your input without installing anything; everything happens client-side.
Do I need an account for Check SSL Certificate (OpenSSL)?
No — Check SSL Certificate (OpenSSL) needs no account, sign-up or installation.
Where is my data processed by Check SSL Certificate (OpenSSL)?
Entirely in your browser — Check SSL Certificate (OpenSSL) keeps your data on your own machine and sends nothing anywhere.
How do I inspect a live site's certificate in Check SSL Certificate (OpenSSL)?
Export the certificate from your browser's padlock as PEM and paste it into Check SSL Certificate (OpenSSL); it decodes the ASN.1/DER fields entirely on your device.
Can I use Check SSL Certificate (OpenSSL) without a connection?
Yes — after the first load Check SSL Certificate (OpenSSL) runs entirely offline.