CoinkiteDiscontinued Open Source USB

Coldcard Mk3

Brand

Coinkite

Connectivity

MicroSD (air-gapped), USB Micro-B

Display

OLED 128×64

Supported Coins

Bitcoin only

Released

2019

Price

Discontinued

About Coldcard Mk3

The Coldcard Mk3 was a security-focused Bitcoin-only hardware wallet from Coinkite, popular among advanced Bitcoin users. It features a full numeric keypad, MicroSD card support for air-gapped PSBT transactions, two secure element chips, and a duress PIN feature. The Mk3 runs fully open-source firmware and is designed for maximum security with no altcoin support. It has been succeeded by the Mk4.