Educational Purpose Only
This tool demonstrates public key compression on the secp256k1 curve. Public keys are not secret, but never enter private key material into any browser tool for real funds.
Public Key Compression
Convert secp256k1 public keys between uncompressed (04 + 64 bytes) and compressed (02/03 + 32 bytes) formats. Enter either format — the tool detects which direction to convert.
How compression works: A secp256k1 public key is a point (x, y) on an elliptic curve.
The uncompressed form stores both x and y (130 hex chars, prefix 04).
The compressed form stores only x and uses the parity of y as a prefix (02 if y is even, 03 if odd).
The full y coordinate can always be recovered from x using the curve equation y² = x³ + 7 (mod p).