@Support @Support, we are still waiting for your response.
3.3/ 5
Our score
Fair
Price from
$219
Secure element
Yes
Firmware
Fully open source
Connectivity
USB-CNFCQR code (air-gapped)microSD
Supported assets
1
Bitcoin-only
Yes
What is COLDCARD?
COLDCARD is a Bitcoin-only hardware wallet from Coinkite Inc. It signs transactions offline and supports QR, MicroSD, NFC and USB transfer methods without requiring a COLDCARD account or companion app. The Q model adds a full keyboard and QR scanner, while the Mk5 is smaller and uses a numeric keypad.
Company and products
Coinkite is a Canadian Bitcoin security company founded in 2012 and headquartered in Toronto. The product range includes COLDCARD Q and COLDCARD Mk5, plus the SEEDPLATE steel backup and COLDPOWER battery-to-USB adaptor. The Q has a larger screen, keyboard, dual MicroSD slots and battery power. The Mk5 has a compact design, Gorilla Glass screen, MicroSD, NFC and USB-C.
How it works
Private keys stay on the signing device, which can operate without touching a computer. Compatible wallet software such as Sparrow, Cove, Nunchuk and Specter creates PSBT files, then COLDCARD signs them through an air-gapped workflow. Transfers can use QR codes, MicroSD, NFC, USB or Virtual Disk. These options are off by default.
Both models use dual secure elements from Microchip and Maxim, with the seed split across the main processor and secure elements. Firmware is open source and reproducible. Users can create or import a seed, use a BIP39 passphrase, set duress and brick PINs, and configure multisig policies. Bitcoin is the only supported chain.
Prices and availability
The listed price is $319 USD for COLDCARD Q and $219 USD for COLDCARD Mk5. Setup works on-device without a required account or companion app. The device supports encrypted backups, MicroSD backups and standard seed recovery, while SEEDPLATE provides a steel backup format with 12 words per side and 24 words total.
Security record
COLDCARD has a public security review record beginning in 2019, with four published independent checks and five fixed firmware release tracks. In July 2026, attackers began draining wallets affected by a seed-generation flaw. The weakness came from a March 2021 configuration that routed some devices to a deterministic fallback random-number generator.
By August 2026, reported losses reached approximately 1,816 BTC from more than 5,200 addresses, valued at about $116 million. Coinkite released patches on July 31, 2026, but firmware updates did not repair seeds created during the affected period. Those seeds require migration.
Limitations and risks
Bitcoin-only support excludes other networks and tokens. Air-gapped signing adds manual backup and PSBT handling. Passphrases and multisig also create recovery procedures that must be recorded accurately. The 2026 incident remains a serious limitation for affected devices and seeds.
Best for:Long-term Bitcoin self-custodyAir-gapped Bitcoin signingMultisig wallet setupsAdvanced offline backups
Pros and cons
Pros
- Bitcoin-only design limits software scope
- Air-gapped signing works without a required app
- Dual secure elements use two chip vendors
- Open, reproducible firmware supports independent checking
- Multisig and BIP39 passphrases support advanced custody setups
Cons
- Supports Bitcoin only, excluding other networks and tokens
- Q costs $319 USD and Mk5 costs $219 USD
- 2026 flaw affected seed generation and requires migration
- Air-gapped PSBT workflows add manual handling
- Physical loss of seed backups can cause permanent loss
Our review
3.3/5
Fair
COLDCARD offers unusually strong offline Bitcoin signing and inspection controls, but the 2026 seed-generation exploit and Bitcoin-only design are serious trade-offs.
COLDCARD is a Bitcoin-only hardware wallet made by Coinkite, a Toronto company founded in 2012. Q adds a full keyboard and QR scanner, while Mk5 is smaller and uses a numeric keypad. Both have dual secure elements from Microchip and Maxim, passphrases, multisig support, and duress PIN tools.
Firmware is open source and reproducible, and the site lists four published independent checks. The clear case and on-device transaction review support device inspection during setup.
The company’s security record has a major exception. A firmware configuration error introduced in March 2021 routed seed generation to a deterministic fallback random-number generator. Attackers began draining affected wallets on July 30, 2026. Reports put the total at about 1,816 BTC from more than 5,200 addresses by August 2026. Coinkite released fixed firmware, but updating the device did not repair seeds created during the affected period, which require migration. This incident is a material security concern for affected seeds.
Prices shown are $219 USD for Mk5 and $319 USD for Q. There is no required KYC or COLDCARD account, and the device supports Bitcoin only, so it has no broad altcoin coverage. COLDCARD has no touchscreen controls and supports Bitcoin only.
Specs
| KYC required ⓘ | No · unverified |
|---|---|
| Price from | $219 · unverified |
| Connectivity | USB-C, NFC, QR code (air-gapped), microSD · unverified |
| Secure element | Yes · unverified |
| Firmware | Fully open source · unverified |
| Display | Screen + buttons · unverified |
| Air-gapped signing | Yes |
| Bitcoin-only | Yes |
| Supported assets | 1 · unverified |
| Battery | Yes · unverified |
| BIP39 passphrase | Yes · unverified |
| Multisig support | Yes · unverified |
| Companion app | No required companion app · unverified |
| Touchscreen | No · unverified |
| Backup options | Seed words, Metal backup, Encrypted MicroSD · unverified |
| NFC | Yes · unverified |
Data from the provider's website and public sources. Fees and availability change; confirm on the official site before you sign up.
Key features
Air-gapped signing
Signs Bitcoin PSBTs without a computer connection through QR codes, MicroSD, NFC or USB.
Dual secure elements
Uses Microchip and Maxim secure elements, splitting the seed across the processor and both chips.
Open firmware
Firmware is open source and reproducible, with device boot checks for signed firmware and flash changes.
Multisig support
Supports multisig policies created on-device and coordinated through compatible software such as Sparrow or Nunchuk.
Passphrase wallets
BIP39 passphrases create separate wallets and must be backed up independently from the seed.
Duress controls
Optional duress, countdown and brick PINs support separate wallets, delays, seed wiping or device destruction.
Multiple transfer paths
QR, MicroSD, NFC, USB and Virtual Disk workflows let users choose how PSBT data moves.
Offline backups
Encrypted MicroSD backups and the separate SEEDPLATE product support recovery without cloud storage.
Inside COLDCARD
COLDCARD Q
The Q is the larger Bitcoin-only signer with a full QWERTY keyboard, 3.2-inch LCD screen, QR scanner, dual MicroSD slots, NFC, USB-C, and battery power.
COLDCARD Mk5
The Mk5 is the smaller model with a bright OLED screen, numeric keypad, MicroSD, NFC, USB-C, and Virtual Disk workflows.
Secure Notes & Passwords
This offline section stores private notes and critical passwords in encrypted settings, keeping them away from cloud notes and daily-use computers.
BIP-85 child seeds
BIP-85 derives separate seed words for other wallets from one master backup, including seeds used by supported external wallets.
Seed Vault
Seed Vault recalls multiple saved secrets on the device, including recovery material for other wallets, without keeping those secrets on a phone.
COLDCARD screenshots
What users say about COLDCARD
Complaints focus on the seed-generation vulnerability, lost funds, weak company communication, and firmware problems.
Top goods
In their own words
“Same here! Updated firmware, rolled dice, extended passphrase. I truly believe rolling the dice and extended passphrase saved my stack. I have two ColdCard Q’s and at $298 plus tax for each. I am not tossing devices that I took no losses using. Hate it or love it but no HWW comes close.”
“Yes, but only for cross checking wallet addresses from my Keystone 3 Pro. Cold card has this nice export feature for receiving and change addresses that no other HWs has.”
“Yes, if you generated your own entropy, it’s a good device for signing transactions offline. For additional peace of mind, you can also set up a multisig with it”
“Any hope for stolen funds? I understand that the possibility that the stolen coins are near zero, if not outright zero. Maybe this is just an attempt to cope with everything that happened, since I have lost all my funds.”
“Unprofessional So no response from support in more than a week. Plus no CEO or statement from those in charge. If this happened to another company there would be better communication and puvlicy statements. Where is nvk? Totally silent. Usually likes to talk but i guess not now”
“PSA: Coldcard Mk4 BRICKED by the new emergency firmware hotfix (seed.py crash). Irony at its finest. Just wanted to put out a serious warning for anyone updating their Coldcard Mk4 to fix the recent RNG/seed generation vulnerability.”
Based on 200 Reddit posts and comments from the last 12 months, checked Oct 18, 2026. These are posts by users on other sites, not reviews submitted on CryptoReview.
User reviews
No user reviews yet. Have you used COLDCARD? Share your experience below.
FAQ
Who founded COLDCARD?
COLDCARD is made by Coinkite Inc., a Bitcoin security company founded in Toronto, Canada, in 2012.
How much does COLDCARD cost?
The COLDCARD Mk5 costs $219 USD and the COLDCARD Q costs $319 USD.
Does COLDCARD require KYC or an account?
COLDCARD can be set up without a COLDCARD account or required companion app, and signing does not require an online account.
Is COLDCARD safe after the 2026 security incident?
Fixed firmware is available for affected release tracks, but seeds generated during the affected period still require migration because updating firmware does not repair them. The incident involved weakened seed randomness and reported losses of about 1,816 BTC across more than 5,200 addresses by August 2026.
Which coins does COLDCARD support?
COLDCARD supports Bitcoin only, including Bitcoin transaction signing through PSBT-compatible wallet software.
Does COLDCARD support air-gapped signing and multisig?
Yes. COLDCARD can sign Bitcoin PSBTs while offline through QR codes, MicroSD, NFC, USB, or Virtual Disk workflows, and it supports multisig setups.
Latest from COLDCARD on X
@Support — urgent escalation requested. A phishing post appeared on our account, yet we can find no corresponding login, session, or access record. Our credentials and offline 2FA remain secure.
This raises concern about unauthorized platform-level or administrative access. We are also aware of reports that access to X administrative accounts is being sold on darknet markets, although we cannot independently verify a connection.
Please preserve all relevant logs and have your security team investigate immediately. This appears to be a targeted, highly specific attack.
This raises concern about unauthorized platform-level or administrative access. We are also aware of reports that access to X administrative accounts is being sold on darknet markets, although we cannot independently verify a connection.
Please preserve all relevant logs and have your security team investigate immediately. This appears to be a targeted, highly specific attack.
We are investigating how a post containing a phishing link was published from this account. It has since been deleted.
Do not visit or interact with that link. COLDCARD’s only official website is https://t.co/KPUcAMDQ4Y.
This account has used offline 2FA with tightly restricted access since 2017. We have contacted @X and are reviewing all account access.
We will share further verified updates here.
Do not visit or interact with that link. COLDCARD’s only official website is https://t.co/KPUcAMDQ4Y.
This account has used offline 2FA with tightly restricted access since 2017. We have contacted @X and are reviewing all account access.
We will share further verified updates here.
Press 2 at the OK TO SEND? screen to open Transaction Explorer. Step through every input being spent and every destination or change output instead of approving from a summary alone.
https://t.co/NCUpLSO1bJ
https://t.co/NCUpLSO1bJ
A clear case is not decoration. It lets you inspect a COLDCARD for a component swap or implant. The tamper-evident bag, anti-phishing words, dual Secure Elements and verified firmware add independent checks. That’s defense in depth.
https://t.co/H1avwQg0CP
https://t.co/H1avwQg0CP
Recent public posts from @COLDCARDwallet, shown as published. Not reviewed or endorsed by CryptoReview.
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