Mnemonic
English BIP-39 only. Passphrase is optional BIP-39 extension (not a PIN on this page).
Mnemonic figure is BIP-39 ENT bits (not Shannon of the words). Passphrase figure is a local estimate only. The BIP-39 seed is always 64 bytes from PBKDF2 — that is output size, not “512 bits of entropy.”
Receive addresses
Think of your recovery phrase as the master key to a bank vault. From that one key, wallets create many different “account numbers” (addresses) so you can receive bitcoin without reusing the same number every time. Everything below is calculated offline on this page — nothing is sent to a bank or the internet.
Like having several bank accounts under the same login (0 = first account, 1 = second, …). Most people only ever use account 0. Changing it creates a completely different set of addresses.
Receive (0) = numbers you share so others can pay you (like your IBAN on an invoice).
Change (1) = internal numbers wallets use for leftover coins after a payment (like a till drawer, not for customers).
How many addresses in a row to list (starting at 0). Like printing the first 5 cheque numbers from the pad. Index 0 is usually the first one a wallet shows you.
Modern wallets mostly use Taproot (bc1p…) and native segwit (bc1q…). Nested (3…) and legacy (1…) are older formats — leave them off unless you need them; that keeps the table wide and readable without sideways scrolling.
What each column means (simple)
- idx — address number in the sequence (0, 1, 2…). Same phrase + same settings always gives the same list.
- BIP86 Taproot (bc1p…) — newest common format; like a modern IBAN. Path style
m/86'/0'/account'/change/index. - BIP84 native segwit (bc1q…) — widely used “bc1q” addresses. Path
m/84'/…. - BIP49 nested (3…) — older “compatibility” style. Path
m/49'/…. Optional. - BIP44 legacy (1…) — oldest style still seen on chain. Path
m/44'/…. Optional.
What this is: public receive numbers only (safe to share one when you want payment).
What this is not: not your recovery phrase, not a private key, not a balance, and not a bank transfer — you still need a real wallet to spend.
| # | BIP86 · Taproot | BIP84 · native segwit | BIP49 · nested | BIP44 · legacy |
|---|---|---|---|---|
| Generate or paste a valid mnemonic to fill addresses. | ||||
Click Copy next to any address to put it on the clipboard (like copying an IBAN). Only the address is copied — never the recovery phrase.
Address balance (CLI)
This page never loads balances (CSP blocks network). Use the CLI so seed material never leaves your machine for a balance check. Public explorers only see the address after you opt in.
Free public review (no Bitcoin Core required) — mempool.space REST:
python -m bip39lab balance bc1q… \ --backend mempool \ --i-understand-address-leak
Your own node (preferred when available):
python -m bip39lab balance bc1q… \ --backend bitcoind \ --rpc-cookie ~/.bitcoin/.cookie
There is no free public Bitcoin Core JSON-RPC for everyone on the Internet. Free checks use explorer REST; real JSON-RPC is your node.
Security model
No retention of mnemonics, entropy, seeds, or private keys.
Production path uses audited browser libraries in the offline bundle.
Brand host: bip39.catalyxt.xyz under Catalyxt (catalyxt.xyz only —
catalyxt.ltd is retired for new work).