Coldcard Mk4

Coldcard Mk4: The signing device for uncompromising Bitcoiners

The Coldcard Mk4 by Coinkite is the hardware wallet for everyone who makes no compromises on security. Designed and manufactured in Canada, the Coldcard sets new standards with its unique dual-secure-element architecture and fully air-gapped usability – built specifically for experienced Bitcoiners who demand maximum control and complete verification.

Air-Gapped: Sign completely offline

The Coldcard never needs to be connected to a computer. Transactions can be signed entirely offline – either via the MicroSD card (PSBT format) or via NFC. This keeps your private keys disconnected from the internet at all times, with no compromises.

Two Secure Elements – double protection

What other hardware wallets solve with a single security chip, the Coldcard Mk4 tackles with two separate secure elements from different manufacturers. Even if one of the chips were to be compromised, the second remains active as an independent layer of protection.

Open-source, verifiable firmware

The Coldcard's entire firmware is open source and can be built deterministically. This means anyone can independently verify that the software running on the device matches the published code exactly. No hidden backdoors, no blind trust.

Anyone who wants to fully understand private keys, transactions, signatures and Bitcoin’s technical foundations will find an ideal deep dive in Mastering Bitcoin.

Secure PIN structure with anti-coercion protection

The Coldcard offers a multi-level PIN system including a «Duress PIN» that opens an alternative wallet – without an attacker noticing the difference. There is also a «Brick Me» PIN that renders the device instantly unusable when entered under duress.

Technical Details

• Security architecture: Two secure elements from different manufacturers
• Connectivity: USB-C, MicroSD (PSBT), NFC (optional)
• Display: Razor-sharp OLED for transaction verification
• Usage: Fully air-gapped capable (no PC required)
• Firmware: Open source, deterministically reproducible, externally audited
• Origin: Made in Canada by Coinkite

What’s included

• Coldcard Mk4 hardware wallet (sealed and shrink-wrapped, directly from Coinkite)

Note: The Coldcard is aimed at experienced users. We recommend reading reviews and consulting Coinkite's official documentation before purchasing. The device is forwarded unopened and in its original seal.

This wallet works excellently with .
→ Link to Pocket