BIP-39 Seed Checksum Calculator & Solver
Resolve "Seed Phrase is Wrong", "Checksum Error", and missing word recovery on Ledger Stax, Flex, Nano, and Trezor. Runs 100% locally in your browser sandbox.
100% Client-Side Air-Gapped Security
All cryptographic operations (SHA-256 bit slicing, entropy hashing, dictionary lookups) run strictly inside your browser memory using the native WebCrypto (crypto.subtle) API. No network packets are transmitted. You can disconnect your internet or save this page offline.
Calculate Valid 24th Words
Enter your first 23 words. The algorithm computes the exact 8 words that satisfy the SHA-256 8-bit checksum.
Words detected: 0 / 23