Tool
Decode a Bitcoin private key from Wallet Import Format back to its raw 64 character hex form. The tool verifies the base58check checksum and tells you whether the key is flagged as compressed. Everything runs locally: your key never leaves this page.
Paste a WIF key above. Decoding and checksum verification run instantly, entirely in your browser.
A WIF string is base58check: a version byte (0x80 for mainnet), the 32 key bytes, an optional 0x01 compression flag, and a 4 byte checksum from double SHA-256. The decoder here validates every layer: the base58 alphabet (no 0, O, I or l), the checksum, the version byte, the payload length, and that the decoded number is a valid secp256k1 key. If anything fails, you get a specific error instead of a wrong key.
Reading the result. Keys starting with 5 decode without a compression flag; keys starting with K or L carry the flag. The hex value is identical either way. The flag only tells wallets which of the two possible addresses to derive. To see those addresses, drop the key into the private key to address tool, or go the other direction with hex to WIF.
Handy for studying the solved Bitcoin puzzles, whose revealed keys circulate in both formats. And the same safety rule as always applies: never paste the key of a funded wallet into any website. This tool is for education, testing and puzzle work.