Coldcard Mk5 Review

The Coldcard Mk5 scores 7.4 out of 10 in our hardware wallet ratings, rescored from current evidence on 1 November 2026. The basis is desk research of Coinkite's Coldcard pages, its store, its security status page and the Coldcard/firmware repository on GitHub. We did not test a device. The Mk5 shares the Coldcard Q's two-vendor chip design and its inspectable firmware, both marked 10. It loses ground on price, now listed at $269, and on asset coverage, because it is Bitcoin-only by design.

How the Coldcard Mk5 scores in hardware wallets

Five criteria apply in this category, each marked 0 to 10 and each worth one fifth of the total, as set out in our ratings methodology.

The overall score is a plain average: (5 + 10 + 10 + 8 + 4) / 5 = 37 / 5 = 7.4.

Change from the previous scoring: price and value fell from 7 to 5. The July review used a $189 list price. Coinkite's store now lists the Mk5 at $269, and the methodology scores the list price, not a sale price. The $219 sale price falls in the same band, so the mark would be 5 either way. The other four marks are unchanged, and the overall score moves from 7.8 to 7.4.

Strongest criteria: the chips and the code

Secure element (10)

Coinkite says the seed is held across two secure elements from different manufacturers, a Microchip ATECC608 and a Maxim DS28C36B. A flaw in one vendor's part is then not enough on its own to expose the seed. Neither chip is quoted with a Common Criteria level. The methodology credits independent multi-chip designs on their own terms, which is why the Mk5 scores above the single certified chips at 9.

Open source (10)

The firmware repository documents reproducible builds, so a release can be shown to match the source. Its hardware folder holds a schematic and a bill of materials for the Mk5 board revision. The licence is MIT with the Commons Clause, which allows anyone to read, build and modify the code but withholds the right to sell it. The criterion scores how much can be inspected, not the licence, so the mark stays at 10.

Weakest criteria: deficiency versus design choice

Asset coverage (4): by design

The Mk5 signs Bitcoin transactions only. Coinkite is a Bitcoin-only company and says so. Bitcoin-only devices score lower here by definition, and the Mk5 gets the same 4 as the Coldcard Q and the Bitcoin-and-Liquid Jade Plus.

Price & value (5): a measured deficiency

At a $269 list price, the Mk5 costs more than every multi-asset device in the category. The category's bands give 5 for $200 to $300. No backup accessory ships with it, and the store listings say the USB cable is not included.

Air-gap & verification (8)

A fully air-gapped workflow exists. A partially signed Bitcoin transaction (PSBT) travels on a microSD card, the device shows the address and amount, and the signed file returns the same way, with the device powered by a USB-C power source only. NFC with PushTX and a USB virtual-disk mode are also offered. The two points below the Q come from the missing QR camera and the single card slot: every air-gapped signature involves moving a card.

What the score does not cover

The rubric has no criterion for incident history, and the most important fact about the Mk5 this year falls outside it. On 30 July 2026 Coinkite disclosed a firmware bug that weakened seed generation. Its security status page, updated 1 October 2026, says attackers regenerated affected keys offline and stole funds. It also says devices were not remotely accessed. What Coinkite tells Mk5 owners:

• Seeds created on Mk4, Mk5 or Q firmware before the fixed releases are covered by the advisory.
• The minimum fixed release for the Mk5 is 5.6.0, and the recommended standard release is 5.6.3.
• Updating firmware does not repair an existing seed. Affected seeds must be replaced and the funds moved.
• A seed made with at least 50 fair, private dice rolls is not considered at risk from this bug alone.

The secure element mark scores the chips that store a seed, not how well the seed was generated, so it is unchanged. Readers should weigh the incident separately. Our guide to what protects your keys in a hardware wallet covers the parts of a hardware wallet's security that can fail. New units ship with corrected firmware, which the store says should be updated on receipt. Durability and support were also not assessed.

Coldcard Mk5 vs the closest rated peers

The Coldcard Q runs the same security model. It scores 0.2 higher because QR signing lifts its air-gap mark by two points, which outweighs its one-point lower price mark ($369 list). The Mk5 ties the BitBox02 at 7.4, and the BitBox02 is listed first alphabetically. The BitBox02 is cheaper and covers more assets, while the Mk5 is stronger on the chips and on cable-free signing.

Who it suits

On the scored evidence, the Mk5 fits Bitcoin-only holders who want two independent secure elements and reproducible firmware, and who will sign over microSD. A numeric keypad is fine for most of them, though Coinkite notes that a long passphrase is easier to type on the Q's keyboard. It does not fit anyone holding other assets, anyone who wants QR signing, or anyone with a Coldcard seed created before the fixed firmware who has not yet migrated it.