How to use Qualys SSL Test
- Add a PEM certificate to Qualys SSL Test to get started.
- Hit Parse certificate and Qualys SSL Test computes the result client-side.
- Use the subject, issuer, validity dates and expiry Qualys SSL Test produces — nothing was uploaded.
About this tool
Qualys SSL Test is a static, client-side tool with no backend. Qualys SSL Test 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. Nothing you enter is uploaded, and it keeps working offline once the page has loaded.
Frequently asked questions
What is Qualys SSL Test for?
Qualys SSL Test runs entirely on your device: add your input, and it checks it locally in real time.
Does Qualys SSL Test cost anything?
No — Qualys SSL Test is completely free, with no sign-up and no hidden limits.
Where is my data processed by Qualys SSL Test?
Entirely in your browser — Qualys SSL Test keeps your data on your own machine and sends nothing anywhere.
How do I inspect a live site's certificate in Qualys SSL Test?
Export the certificate from your browser's padlock as PEM and paste it into Qualys SSL Test; it decodes the ASN.1/DER fields entirely on your device.
Can I use Qualys SSL Test without a connection?
Yes — after the first load Qualys SSL Test runs entirely offline.