How to use OpenSSL Test Key and Cert
- Paste or load a PEM certificate into OpenSSL Test Key and Cert.
- Press Parse certificate to run it locally in your browser.
- Read the subject, issuer, validity dates and expiry that OpenSSL Test Key and Cert lays out for you.
About this tool
OpenSSL Test Key and Cert is a static, client-side tool with no backend. Paste a PEM certificate and OpenSSL Test Key and Cert parses the X.509 fields entirely on your device.
To check a live site, export its certificate from the browser padlock as PEM and paste it here. Nothing you enter is uploaded, and it keeps working offline once the page has loaded.
Frequently asked questions
What is OpenSSL Test Key and Cert for?
Use OpenSSL Test Key and Cert to check your input without installing anything; everything happens client-side.
Do I need an account for OpenSSL Test Key and Cert?
No — OpenSSL Test Key and Cert needs no account, sign-up or installation.
Is my input private in OpenSSL Test Key and Cert?
Yes — your input never leaves your device; OpenSSL Test Key and Cert does all the work in your browser.
How do I inspect a live site's certificate in OpenSSL Test Key and Cert?
Export the certificate from your browser's padlock as PEM and paste it into OpenSSL Test Key and Cert; it decodes the ASN.1/DER fields entirely on your device.
Does OpenSSL Test Key and Cert work offline?
Once the page has loaded, OpenSSL Test Key and Cert keeps working with no network connection.