Buy Coldcard Mk3

Dual Secure Element

It provides the best Physical Security. Your seed words are stored in specialized chips, designed solely to securely store secrets. Now dual-vendor!

Verifiable Source Code

All of the Coldcard code is viewable, editable, and verifiable. You can compile it yourself.

True Air-gap

Only signing device (hardware wallet) with option to avoid ever being connected to a computer, for its full life cycle: from seed generation, to transaction signing. Uses PSBT (BIP174) natively!

The Coldcard looks a lot like a calculator. You can connect the wallet to your computer or use it completely air-gapped with the apps Bitcoin Core, Spectre, Electrum, BlueWallet and Wasabi Wallet.

PSBT (Partially Signed Bitcoin Transaction), one of the advanced features of the wallet, allows you to sign transactions offline. The information is stored in a micro SD card (not included and needs to have a maximum of 32GB) that you can plug into your computer. This way, the Coldcard is never linked directly to your computer. A hacker cannot access your wallet.

Supplied as standard:

• ColdCard wallet
• Paper to write down your 24 words
• ColdCard sticker – nice to stick on your laptop