Learn Bitcoin by doing.
A real wallet on practice networks where mistakes cost nothing — every address type, free coins, and plain-English explainers as you go. Start with the basics →
- Tap Generate new, then Open wallet. Write the words on paper.
- Receive: copy your address, get free coins from the faucet.
- Send anywhere — then explore every address type in Accounts.
Non-custodial · open source · verify everything
History
RefreshAccounts
One seed → every Bitcoin address type. Tap any to receive, send, or learn what makes it different.
Account
· about ▾
History
Send
From — · —
Genuine uses: proving a document existed at a point in time, notarising, attribution, a personal message or memorial.
The famous one: Satoshi wrote a newspaper headline — "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks" — into the very first block. OP_RETURN is today's tidy way to leave your own mark like that.
Where we stand: people disagree about what data belongs on Bitcoin. Olesia is neutral — it's part of the protocol, so it's here, explained, for you to use thoughtfully. (No NFTs or inscriptions.)
Learn Bitcoin
Every concept in plain English — then try it for real. Progress saves on this device.
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Want the long version with diagrams? olesia.io/learn →
Settings
Wallet
Security
Saves your seed encrypted (scrypt + XChaCha20-Poly1305 — the cold generator's own crypto). Plaintext never touches disk; your PIN decrypts it in memory. A weak PIN on a compromised device is still a risk — real money belongs in cold storage.
Advanced
Watch-only online: Build unsigned (uses the Send screen's fields) → sign offline → Broadcast here. The seed never needs to be online.
About
Balances/broadcast via mempool.space (mainnet broadcast via api.olesia.io). No analytics, no server-side storage. Signing with @scure/btc-signer, in your browser.