Certificate Decoder · Free online tool · 100% offline · No data collection Open in App
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What is Certificate Decoder?

Certificate Decoder is a free online developer tool that decode and inspect X.509 SSL/TLS certificates to view expiry, issuer, and SANs. Like all FluxBench tools, it runs entirely offline in your browser — no data is ever sent to any server.

How to use Certificate Decoder

1 Open the Certificate Decoder tool on FluxBench
2 Decode and inspect X.509 SSL/TLS certificates to view expiry, issuer, and SANs
3 Copy or download your result — ready to use

Common use cases

Frequently Asked Questions

Is Certificate Decoder free to use?

Yes, Certificate Decoder is completely free on FluxBench. No account, no signup, no payment required.

Does Certificate Decoder send my data anywhere?

No. All FluxBench tools run 100% offline in your browser. Your data never leaves your device — we have no backend servers.

Can I use Certificate Decoder on mobile?

Yes, FluxBench works on any modern browser including mobile. Just open the tool page on your phone or tablet.

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