Free, browser-based utilities for everyday developer workflows

Certificate & PEM Tools

Decode X.509 certs, inspect CSRs, and split PEM chains locally.

Use cases

Decode an X.509 Certificate

Explore more in the Use cases library.

Mode

Certificate input

Summary

Raw JSON

How to use Certificate & PEM Tools

Paste a PEM-encoded certificate, CSR, or certificate chain into the input. The tool will decode and display the human-readable fields including subject, issuer, validity dates, SANs, and key usage flags.

Common use cases

Security engineers use this to inspect TLS certificates during troubleshooting or audits. DevOps teams use it to validate certificate chains before deployment, and developers use it to decode CSRs before submitting them to a CA.

Why run this in your browser?

All processing happens locally in your browser. Your data never leaves your machine, making it safe for sensitive payloads, internal API responses, and confidential configurations.