PEM/DER Converter
Convert certificates and keys between PEM and DER encoding.
PEM input
Drop a file here
Drop a .pem or .der/.crt file
Output
About the PEM/DER Converter
Convert between PEM (Base64-armored) and DER (binary) representations of certificates, keys, and other ASN.1 structures. Automatically detects the PEM label, and lets you download the result as a .der or .pem file.
Examples
Convert PEM to DER
-----BEGIN CERTIFICATE-----...Output
30 82 01 22 30 0d ...Keyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
- OpenSSL commands and key formats, explained without the man page
CSRs, self-signed certificates, PEM vs DER vs PKCS#8 vs JWK, and how to check what a certificate actually contains.
Version 1.0.0 · Updated 2026-08-10 · Runs entirely in your browser