Certificate Decoder — Decode SSL/TLS Certificates Online Free
Parse the first PEM certificate or CSR and identify other PEM block types in your browser.
Jump to tool ↓Frequently Asked Questions
Universal Certificate & PEM Decoder
PEM (Privacy Enhanced Mail) is the most common encoding format for cryptographic objects like SSL certificates, CSRs, private keys, and public keys. A PEM file is a Base64-encoded DER (Distinguished Encoding Rules) structure wrapped in -----BEGIN TYPE----- and -----END TYPE----- delimiters.
This decoder checks the first PEM block. X.509 certificates show subject, issuer, validity, SANs, and fingerprints. CSRs show requested subject and public key. Other block types are identified by their headers; their contents are not parsed here. To inspect a chain, paste each certificate separately.
Parsing runs in your browser. This page does not require a private key to decode a certificate or CSR.
Standards & References
Built and maintained by DevDecode. This tool processes your input in your browser; it is not uploaded for processing. Found an issue? Let us know.
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