decoder.tools

PGP / GPG Armored Decoder

Remove the ASCII armor from a PGP key or message and inspect the packets inside.

Security, PKI & CryptoFree
INPUT

Or drop a file here: an ASCII-armored .asc or binary .gpg file

OUTPUT

The result appears here as you type.

Decoding runs in your browser. What you paste is not sent to a server.

A PGP armor decoder strips the -----BEGIN PGP …----- wrapper from a key, signature or message and lists the OpenPGP packets inside, such as key packets, user IDs, signatures and encrypted session keys.

Example

A public key block decodes to its packets, user ID and key details:

Public Key: v4, EdDSA, created 2026-10-23
User ID: Ada Lovelace <ada@example.com>
Signature: v4 signature

For an encrypted message, the Public-Key Encrypted Session Key packets reveal which key IDs it was encrypted to.

ASCII armor and packets

OpenPGP (RFC 9580, which replaced RFC 4880) data is binary and made of packets. To paste it into email or a web page it is ASCII-armored: Base64 with a header line, optional Key: value headers, and a CRC-24 checksum line starting with =.

Armor headerContents
BEGIN PGP PUBLIC KEY BLOCKPublic key, user IDs and self-signatures
BEGIN PGP PRIVATE KEY BLOCKSecret key, usually passphrase-protected
BEGIN PGP MESSAGEEncrypted and/or signed message
BEGIN PGP SIGNATUREDetached signature
BEGIN PGP SIGNED MESSAGEClear-signed text followed by a signature

Common packets: public-key (tag 6), user ID (tag 13), signature (tag 2), public-key encrypted session key (tag 1) and encrypted data (tags 18 and 20).

How to use the PGP decoder

  1. Paste a -----BEGIN PGP …----- block, or open a .asc / .gpg file.
  2. Read the packet list: public-key and subkey packets, user IDs, signatures and (for messages) the recipient key IDs.
  3. The armor's CRC-24 checksum is verified, so you'll know if the block was damaged in copy-paste.

gpg --list-packets shows the same packets on the command line:

Command line
# Show the packets in a key or message
gpg --list-packets key.asc

# Show key IDs, user IDs and algorithms without importing
gpg --show-keys key.asc

At a glance

SpecificationRFC 9580 (OpenPGP), formerly RFC 4880
ArmorBase64 plus a CRC-24 checksum
Key IDLast 8 bytes of the fingerprint
Modern algorithmsEd25519 / Cv25519 (ECC), RSA 3072+

Frequently asked questions

Can I see who a message is encrypted to?

Usually yes. Each recipient gets a public-key encrypted session key packet containing their key ID, unless the sender hid it with --throw-keyids.

Is it safe to share a PGP public key?

Yes. Public keys are meant to be published. Never share a PRIVATE KEY BLOCK.

What is the line starting with = at the end?

It's the CRC-24 checksum of the armored data, which detects copy-paste damage. It has nothing to do with the signature.

Last reviewed · found a mistake? contact@decoder.tools · view as markdown