Free tool · 100% in-browser
DKIM key converter
Paste a public key PEM, a private key PEM (like a PowerMTA .private file), or an existing DKIM record — the converter auto-detects it and gives you every form: the public key PEM, the p= value, the DNS TXT record, the host, and the PowerMTA domain-key line. All local; your private key never leaves the browser.
Converter FAQ
What does the DKIM key converter do?+
Paste a public key PEM, a private key PEM, or an existing DKIM record (or just the p= value), and it produces every form you need: the public key as PEM, the DKIM p= value, the full DNS TXT record (plus a split version), the DNS host, and the matching PowerMTA domain-key line. It works out the real key size too.
Is it safe to paste my private key?+
Yes — everything happens in your browser with the Web Crypto API; nothing is uploaded. The converter only reads the public portion it needs from a private key to build the DNS record. Still, only paste private keys on a machine you trust, and never publish a private key in DNS.
I have a .private file from PowerMTA — how do I get the DNS record?+
Open the .private key file, paste its PEM contents here, and the converter derives the public key and gives you the DKIM TXT record to publish, the DNS host (selector._domainkey.domain) and the exact domain-key line for /etc/pmta/config.
Does it support Ed25519 keys?+
The converter focuses on RSA keys, which are what almost all DKIM setups use. Ed25519 DKIM exists but is far less common; for it, use the raw 32-byte key value directly in your DKIM record.
Related: DKIM checker · DKIM in PowerMTA