ShopColdcard is made by Coinkite Inc., a Bitcoin security company founded in 2012. We build tools for people who want full ownership and custody of their Bitcoin. Our hardware devices keep private keys offline and sign Bitcoin transactions without those keys ever touching the internet. They are Bitcoin-only, air-gapped, and run fully open-source firmware. Those are the gold standards for Bitcoin self-custody security.
Who We Are
Coinkite was founded in Toronto, Canada in 2012. The team is made up of security engineers, product designers, and Bitcoiners who share a common philosophy of security-first.
We are a Bitcoin-only company by design. Staying focused on Bitcoin means a simpler, more auditable codebase, a smaller attack surface, and a team whose full attention stays on one problem: securing Bitcoin.
Genuine security and convenient security are not the same thing, and conflating them is how keys get compromised. We never trade one for the other, and every security claim Coldcard makes is independently verifiable. The firmware is open source, MIT licensed, and reproducibly buildable, maintained by a community that holds us to that standard.
Coldcard devices are designed and assembled in Canada.
What We Believe
Sovereignty is the foundation of freedom. Sovereignty is the ability to hold, verify, and transact your wealth without depending on any person, government, or company. Secure self-custody of Bitcoin is how you pursue sovereignty and Coldcard is built on the principles that make that possible.
-
Bitcoin-only. A Bitcoin-only architecture keeps the codebase focused and auditable, with the team's full attention on one problem. It is a security decision, not a limitation.
-
Air-gapped signing. Any connection to a networked machine is a potential attack vector. Coldcard signs Bitcoin transactions without connecting to an internet-connected computer, removing that attack surface entirely.
-
Open and verifiable. Security claims that cannot be independently checked are just marketing. Coldcard's firmware is open source, MIT licensed, and reproducibly buildable. Everything it claims to do, you can verify for yourself.
-
Self-custody is a practice, not a product. Custody is never a solved problem. It requires ongoing attention as threats evolve and a willingness to revise your approach. Coldcard operates the same way, in a never-ending pursuit of better, more secure custody solutions.
What We Make
Coldcard Q
The Coldcard Q is our most capable signing device, featuring a full QWERTY keyboard, large color display, built-in QR code scanner, NFC, microSD, USB-C, and battery operation via USB-C power bank or AAA batteries. It supports the full range of Coldcard security and custody options and is designed for anyone who wants the most complete air-gapped signing experience available.
Coldcard Mk5
The Coldcard Mk5 is built on the same security foundation as the Q, in a more portable and low-profile form factor. It's credit card-sized and fits in your pocket for convenient and discreet storage and transportation. It supports microSD and NFC tap signing and handles the full range of custody and multisig configurations, making it the right device when portability is the priority.
The Coinkite Ecosystem
Beyond Coldcard, Coinkite builds a range of Bitcoin tools for every layer of a self-custody setup:
- Opendime: a Bitcoin bearer instrument on a USB stick for spending Bitcoin physically, like cash
- Tapsigner: an NFC card that stores a private key for mobile Bitcoin signing
- Satscard: a reusable NFC card for giving and receiving Bitcoin
- Seedplate: a stainless steel plate for fireproof and waterproof seed phrase backup
- Blockclock: a Bitcoin clock that displays real-time network data
Open Source
All Coldcard firmware source code is available at github.com/coldcard. It is MIT licensed, reproducibly buildable, and under active development. You can read it, build it from source, and verify exactly what your device is running.
When code is public and auditable, security properties are verifiable facts. Not vendor promises.
Connect
- Documentation: coldcard.com/docs
- Store: store.coinkite.com
- GitHub: github.com/coldcard
- Twitter/X: @COLDCARDwallet
- Telegram: t.me/coldcard
Coldcard is made by Coinkite Inc., Toronto, Canada. Bitcoin-only. Air-gapped. Open source.