Learn Bitcoin and how to hold your own keys.https://21millionbitcoin.org/https://21millionbitcoin.org/guides/cold-storage-kits/https://21millionbitcoin.org/guides/cold-storage-kits/Four complete cold storage builds, from a free one-hour setup to a 2-of-3 multisig vault, with costs, trade-offs and who each one is for.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/common-mistakes/https://21millionbitcoin.org/guides/common-mistakes/The real ways people lose bitcoin, from lost backups and fake support agents to clipboard malware, and the simple habits that prevent each one.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/cold-storage-without-hardware/https://21millionbitcoin.org/guides/cold-storage-without-hardware/Build a true cold wallet with free software: Tails on an offline computer, Sparrow Wallet, and offline signing with PSBT files or QR codes.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/air-gapped-laptop/https://21millionbitcoin.org/guides/air-gapped-laptop/How to pick a cheap laptop for offline Bitcoin signing, physically remove its Wi-Fi and Bluetooth, and set it up with Tails and Sparrow.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/build-a-seedsigner/https://21millionbitcoin.org/guides/build-a-seedsigner/Build an open-source Bitcoin signing device for about $50–70. Parts list, assembly, creating a seed with dice, and signing with Sparrow by QR code.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/hot-vs-cold/https://21millionbitcoin.org/guides/hot-vs-cold/The difference between hot wallets and cold storage, what 'air-gapped' means, and how to decide how much security your bitcoin needs.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/not-your-keys/https://21millionbitcoin.org/guides/not-your-keys/What private keys and seed phrases are, why exchanges are a risk, and what it takes to hold bitcoin yourself without losing it.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/inheritance-plan/https://21millionbitcoin.org/guides/inheritance-plan/How to write a letter of instructions so your family can recover your bitcoin, what to leave out, and how multisig makes inheritance safer.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/hardware-wallets-compared/https://21millionbitcoin.org/guides/hardware-wallets-compared/Coldcard, Keystone, Passport, Jade, Trezor and BitBox compared: coins supported, air-gap method, open source status, price and who each one fits.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/multisig-2-of-3/https://21millionbitcoin.org/guides/multisig-2-of-3/How a 2-of-3 multisig wallet works, why to use three different devices, how to set it up in Sparrow, and how to back up and test it.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/what-is-bitcoin/https://21millionbitcoin.org/guides/what-is-bitcoin/A plain-English introduction to Bitcoin: what it is, how new coins are made, why the supply is capped at 21 million, and what owning it means.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/seed-backups/https://21millionbitcoin.org/guides/seed-backups/How to back up a Bitcoin seed phrase so it survives fire, flood and time, where to keep it, and whether to add a passphrase.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/practice-on-signet/https://21millionbitcoin.org/guides/practice-on-signet/Use Bitcoin's free test network to rehearse receiving, signing and restoring a wallet, so your first real mistake costs nothing.Wed, 11 Nov 2026 00:00:00 GMThttps://21millionbitcoin.org/guides/buy-and-withdraw/https://21millionbitcoin.org/guides/buy-and-withdraw/Buy bitcoin safely, understand the fees, and withdraw it to a wallet you control, with a test transaction first so nothing goes to the wrong place.Wed, 11 Nov 2026 00:00:00 GMT