COLDCARD Q

The COLDCARD Q is a Bitcoin-only signing device from Coinkite, a company that says its devices are designed and assembled in Canada. It pairs a QWERTY keyboard with a 3.2-inch, 320 x 240 LCD, and it can exchange data over a QR scanner, NFC, two microSD slots or USB-C. It was listed at $319, marked down from $369, on Coinkite’s store on 14 October 2026. This page is built from Coinkite’s documentation and advisories; we have not used the device.

Who is the COLDCARD Q for?

It is built for people who already hold bitcoin in self-custody and want the signing device kept away from their computer. Coinkite’s product page says there is no COLDCARD account and no required companion app: you pair the Q with coordinator software of your choice. The device supports long BIP-39 passphrases and multisig policies.

It suits fewer people if you:

• hold coins other than bitcoin, since Coinkite describes itself as a Bitcoin-only company;
• want a phone app that walks you through setup and shows balances;
• want something pocket-sized: Coinkite’s spec sheet lists 120 x 75 x 22 mm and 93 g without batteries.

If self-custody is new to you, start with our self-custody guide.

Is the COLDCARD Q air-gapped?

It can be run that way. Coinkite’s product page states that a COLDCARD never needs to touch a computer, and the Q has three channels besides USB-C: the QR scanner, an NFC antenna and dual microSD slots. Power can come from three AAA cells (not included) or USB-C, so even power does not require a computer.

Air-gapped Bitcoin signers generally pass unsigned and signed transactions back and forth in the Partially Signed Bitcoin Transaction format (BIP-174): the coordinator on a computer builds the transaction, the signer adds its signature, and the result goes back for broadcast. Our guide to air-gapped hardware wallets covers what this protects against and what it does not.

Coinkite names the full keyboard, with the large screen and QR scanner, as the Q’s defining features. The keyboard lets you type a long passphrase on the device itself rather than on a connected computer.

Does the COLDCARD Q have a secure element?

It has two, from different vendors: a Microchip ATECC608 and a Maxim DS28C36B. A secure element is a chip designed to protect secrets and resist extraction, including physical probing, and Coinkite’s design does not rely on a single chip maker for that job. Our records do not include a security certification level for either chip.

Is COLDCARD open source?

The firmware source is public on GitHub, but it is licensed under MIT plus the Commons Clause, which withholds the right to sell the software or a product whose value derives substantially from it. The Open Source Definition requires that a licence not restrict anyone from selling the software, so COLDCARD firmware is better described as source-available. Anyone can read and audit the code; the restriction is commercial. Trezor takes a different approach, covered in COLDCARD vs Trezor.

How do you back up a COLDCARD Q?

The standard backup is a 24-word BIP-39 seed phrase, and Coinkite’s FAQ says COLDCARD works with 12- or 24-word BIP-39 seeds. Because BIP-39 is a shared standard, the same words can restore the wallet on other compatible software or hardware. An optional passphrase creates a separate wallet from the same words; BIP-39 notes that every passphrase produces a valid wallet, so a mistyped passphrase opens a different wallet instead of showing an error.

For split backups, Q firmware 1.5.3Q added codex32 (BIP-93), a Shamir secret-sharing format whose specification is designed so that shares can be checked and recombined with pen and paper. Splitting an existing seed-word wallet uses Coinkite’s CW1 extension, which is not part of BIP-93, so recovering those shares needs COLDCARD firmware or software that supports it. Codex32 is not SLIP-39: BIP-93 states that SLIP-39 shares cannot be converted directly into codex32 shares, and we found no native SLIP-39 support documented for the Q. Our seed phrase guide compares the formats.

Coinkite also documents an encrypted backup file: a 7z archive on microSD with AES-256 encryption, locked by a random 12-word password unrelated to the seed words. The file is useless without that password, so Coinkite suggests storing the two apart.

What happened with the COLDCARD seed-generation bug?

On 30 July 2026 Coinkite published an advisory stating that a firmware bug weakened seed generation on several COLDCARD models, and that attackers regenerated private keys from weak seeds offline and stole funds. Coinkite says the devices themselves were not remotely accessed. For the Q, seeds generated before standard firmware 1.5.0Q (or Edge 6.6.0QX) are affected. The advisory describes the impact on the Mk4, Mk5 and Q as less severe than on the older Mk2 and Mk3, but still serious.

What Coinkite tells owners:

• Updating firmware does not repair an existing seed. Update first, generate a new seed on fixed firmware, test it, then move funds.
• Keep the old backup until the move is complete and confirmed.
• Coinkite’s security status page, revised on 1 October 2026, lists 1.5.3Q as the recommended standard release.

Both pages discuss reduced risk for seeds created with enough private dice rolls; read the status page before deciding whether a particular seed needs migrating.

What coins and software does the COLDCARD Q support?

Bitcoin only. Coinkite requires no companion app, so the coordinator software (the program that tracks balances, builds transactions and handles multisig setups) is your choice. That flexibility assumes you already know which coordinator you want; for one maker’s app covering several coins, see Ledger vs Trezor.

What we could not verify

• When the Q first shipped to customers.
• Which coordinator apps Coinkite supports over each channel (QR, NFC, microSD). The product page lists the hardware, not the compatibility matrix.
• How the July 2026 losses split by model. The parts of the advisory we read do not break them down.
• Every backup option beyond those above; Coinkite documents further methods we have not reviewed.