Certificate Converter

Convert certificates and private keys between PEM, DER, and PFX / PKCS#12 formats. Runs 100% in your browser — private keys and passphrases never leave your device.

Input · drop multiple files to build a PFX

Drop one or more files — e.g. cert.pem + key.pem (+ optional chain.pem) to build a PFX. Also accepts .crt / .cer / .der / .pfx / .p12 / .key.

Output format

PFX / PKCS#12

Binary bundle (Windows / Java keystores)

PEM bundle

Key + cert(s) in one PEM file

PEM cert only

.pem / .crt

PEM key only

.key

DER cert

.cer / .der binary

DER key

PKCS#8 binary

🔐 Output passphrase (optional)

🔒 Your cryptographic material stays local. Keys, certificates, and passphrases are processed only in this browser tab — no bytes cross the network.

Certificate Converter

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