X.509 certificate decoder

How to use this tool

Inspect a PEM certificate without uploading it.

Enter your content or open a file, then select Run.

Example input

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Local processing

Your input stays in this browser. Drafts are kept in page memory while switching tools, and disappear on reload.

Text is limited to 1 million characters. Regex runs in a worker, capped at 200,000 characters, 1,000 matches and 1.5 seconds. Inputs above 100,000 characters use manual refresh.

The first page load and on-demand modules require network access. A complete offline cache is not included.