# COLDCARD

> COLDCARD is a Bitcoin-only hardware wallet by Coinkite Inc.
> This file provides live, AI-friendly context for products, firmware, and documentation.

## Live stats


- Firmware files indexed: 117
- Platforms covered: 8
- Latest release date: 2026-07-01

## Top firmware platforms (live)

- 1. COLDCARD Mk4 (MK4): 43 files, latest 5.4.5
- 2. COLDCARD Q (Q1): 42 files, latest 1.4.1Q
- 3. COLDCARD Mk3/Mk2 (MK3): 12 files, latest 4.1.9
- 4. EDGE_MK4 (EDGE_MK4): 9 files, latest 6.4.1X
- 5. EDGE_Q (EDGE_Q): 5 files, latest 6.5.0QX


## Key links

- Product pages: https://coldcard.com/q and https://coldcard.com/mk5
- Downloads: https://coldcard.com/downloads
- Documentation: https://coldcard.com/docs/
- F.A.Q: https://coldcard.com/faq
- Start checklist: https://coldcard.com/start/ (first run, Q vs Mk5, no app lock-in, backup first)
- Compare hub: https://coldcard.com/compare/ (Ledger, Trezor, Bitkey, Jade, and BitBox alternatives)
- Learn Center: https://coldcard.com/learn/ (self custody, air-gap, PSBT, seed backup, and multisig guides)
- Hardware wallet comparison: https://coldcard.com/docs/compare-other-wallets/ (full table in llms-full.txt)
- AI context JSON: https://coldcard.com/api/ai-context
- Full AI context: https://coldcard.com/llms-full.txt

## Special Pages
- [Special Pages](https://coldcard.com/special/): Special content pages not shown as part of a group
- [About Coldcard](https://coldcard.com/special/about-page): Coldcard devices are Bitcoin-only hardware wallets made by Coinkite Inc. in Toronto, Canada. They are built on three core security principles: Bitcoin-only, air-gapped signing, and open-source verifiable firmware.
- [COLDCARD FAQ](https://coldcard.com/special/coldcard-frequently-asked-question): Frequently asked questions about COLDCARD — seed words, PINs, firmware upgrades, backups, secure elements, PSBT, and more.


## Compare Bitcoin Hardware Wallets
- [Compare Bitcoin Hardware Wallets](https://coldcard.com/compare/): See how Coldcard compares to Ledger, Trezor, Bitkey, and other devices across security architecture, features, and pricing, side by side.
- [Coldcard vs Ledger Nano X](https://coldcard.com/compare/coldcard-vs-ledger-nano-x): Coldcard is a Bitcoin-only signing device with air-gapped operation and fully open-source verifiable firmware. Ledger Nano X supports thousands of assets over USB or Bluetooth and depends on the Ledger Wallet app.
- [Coldcard vs Trezor Safe 7](https://coldcard.com/compare/coldcard-vs-trezor-safe-7): Coldcard eliminates internet-connected attack surfaces through air-gapped signing with no USB or Bluetooth required. Trezor Safe 7 requires a live connection for every signing operation.'s always-connected architecture.
- [Coldcard Q vs Mk5](https://coldcard.com/compare/coldcard-q-vs-mk5): Coldcard Q and Coldcard Mk5 are both built on open-source firmware and security architecture. The Q adds a QWERTY keyboard, QR scanner, and battery power. The Mk5 is compact with MicroSD and NFC signing.
- [Coldcard vs Bitkey](https://coldcard.com/compare/coldcard-vs-bitkey): Coldcard gives you full key sovereignty with no third-party key and no manufacturer dependency. Bitkey uses a 2-of-3 multisig model where Block holds one key and recovery depends on their infrastructure.
- [Coldcard vs BitBox02](https://coldcard.com/compare/coldcard-vs-bitbox02): Coldcard vs BitBox02 Bitcoin-only compared: both devices run open-source firmware and focus on Bitcoin security. See how they differ on air-gapped signing, seed management depth, and coordinator independence.
- [Coldcard vs Keystone 3 Pro](https://coldcard.com/compare/coldcard-vs-keystone-3-pro): Coldcard vs Keystone 3 Pro compared: both devices are open-source and air-gapped. See how they differ on firmware scope, Bitcoin-specific tooling, and seed management.
- [Coldcard vs Ledger Flex](https://coldcard.com/compare/coldcard-vs-ledger-flex): Coldcard vs Ledger Flex compared: Ledger Flex is a secure-touchscreen multi-asset hardware wallet; Coldcard is a Bitcoin-only, air-gapped hardware wallet for sovereign Bitcoin storage.
- [Coldcard vs Tangem](https://coldcard.com/compare/coldcard-vs-tangem): Compare Coldcard and Tangem for offline Bitcoin signing, mobile multi-asset use, seed recovery, firmware transparency, and physical security.


## Learn Bitcoin
- [Learn Bitcoin](https://coldcard.com/learn/)
- [What is Bitcoin?](https://coldcard.com/learn/bitcoin-basics/what-is-bitcoin): Bitcoin is a peer-to-peer electronic cash system that operates without a central authority. Transactions are verified by a distributed network and recorded permanently on a public ledger. No institution can freeze accounts, reverse confirmed transactions, or issue coins beyond the fixed supply of 21 million.
- [How Does a Bitcoin Transaction Work?](https://coldcard.com/learn/bitcoin-basics/how-bitcoin-transactions-work): Bitcoin transactions consume amounts you control and create new ones. Learn how inputs, outputs, fees, and confirmation work.
- [What are Private Keys and Public Keys?](https://coldcard.com/learn/bitcoin-basics/private-keys-and-public-keys): Private keys prove ownership. Public keys enable verification. Learn how the Bitcoin key pair works and why the private key must stay secret.
- [What is a Bitcoin Wallet?](https://coldcard.com/learn/bitcoin-basics/what-is-a-bitcoin-wallet): Bitcoin wallets store private keys, not bitcoin. Learn how they work and the difference between custodial and self-custodial arrangements.
- [What Gives Bitcoin Value?](https://coldcard.com/learn/bitcoin-basics/what-gives-bitcoin-value): Bitcoin derives value from its monetary properties: a fixed supply, no issuing authority, and verification that requires no trust.
- [What is Bitcoin Self-Custody?](https://coldcard.com/learn/self-custody/what-is-bitcoin-self-custody): Self-custody means controlling your Bitcoin private keys directly, without delegating that control to an exchange or custodian. When you control the keys, no third party can freeze, seize, or lose your funds on your behalf. When you don't, you own a claim against someone else's balance, not bitcoin itself.
- [A History of Bitcoin Exchange Failures](https://coldcard.com/learn/self-custody/bitcoin-exchange-failures): Exchange failures have cost Bitcoin holders billions. This article documents the collapses that make the case for holding your own keys.
- [Bitcoin Security Threat Models](https://coldcard.com/learn/self-custody/bitcoin-security-threat-models): Learn to build a Bitcoin security threat model: what you are protecting, who might threaten it, and what measures are proportionate to the risk.
- [The Spectrum of Bitcoin Custody Options](https://coldcard.com/learn/self-custody/bitcoin-custody-options): Bitcoin custody exists on a spectrum from exchange accounts to air-gapped hardware. Learn what each arrangement means and who controls the keys.
- [The Risks of Holding Cash in a Bank](https://coldcard.com/learn/self-custody/risks-of-holding-cash-in-a-bank): Bank deposits carry inflation, counterparty risk, and capital controls. Learn how these structural risks compare to Bitcoin self-custody.
- [Why Bitcoiners Choose Hardware Wallets](https://coldcard.com/learn/self-custody/why-use-a-hardware-wallet): Hardware wallets keep private keys permanently offline. Learn why the distinction between online and offline key storage defines Bitcoin security.
- [How Bitcoin Wallets Work](https://coldcard.com/learn/how-bitcoin-works/how-bitcoin-wallets-work): A Bitcoin wallet generates and stores private keys, which are the credentials that authorize spending. Bitcoin itself exists as entries on the blockchain, not inside the wallet. The wallet tracks which addresses belong to its keys, monitors the blockchain for incoming funds, and constructs the signed transactions needed to send them.
- [What is a Bitcoin Private Key?](https://coldcard.com/learn/how-bitcoin-works/bitcoin-private-key): A private key is a randomly generated 256-bit number from which every Bitcoin address it controls is mathematically derived. Ownership of bitcoin is, at a technical level, possession of the private key. The key is never broadcast to the network; what gets sent is only the cryptographic signature it produces.
- [What is Public Key Cryptography?](https://coldcard.com/learn/how-bitcoin-works/public-key-cryptography-bitcoin): Public key cryptography lets Bitcoin prove ownership without revealing the private key. Learn how key pairs and digital signatures work.
- [What is a Bitcoin Address?](https://coldcard.com/learn/how-bitcoin-works/what-is-a-bitcoin-address): Bitcoin addresses are derived from public keys. Learn what address formats mean, how generation works, and why address reuse reduces privacy.
- [What Are Bitcoin Hash Functions?](https://coldcard.com/learn/how-bitcoin-works/bitcoin-hash-functions): Learn what hash functions are, why they are one-way, and how Bitcoin uses them across address generation, transaction IDs, and proof of work.
- [What is a Bitcoin Seed Phrase?](https://coldcard.com/learn/how-bitcoin-works/what-is-a-seed-phrase): A seed phrase is 12 or 24 words that generates every key in a Bitcoin wallet. Learn how it works and why it is the only backup that matters.
- [HD Wallets and Bitcoin Derivation Paths](https://coldcard.com/learn/how-bitcoin-works/bitcoin-derivation-paths): HD wallets derive every key from one seed. Learn how derivation paths work and why the path matters when restoring or recovering a wallet.
- [What is a Hardware Wallet?](https://coldcard.com/learn/hardware-wallets/what-is-a-hardware-wallet): A hardware wallet is a dedicated device that stores private keys in isolated hardware and signs transactions without exposing those keys to any connected computer. The keys are generated on the device and never leave it. Signing happens internally, and only the completed signed transaction is passed back to the host software.
- [Hot Wallet vs. Cold Wallet](https://coldcard.com/learn/hardware-wallets/hot-wallet-vs-cold-wallet): A hot wallet keeps private keys on an internet-connected device. A cold wallet keeps them offline. Learn the difference, the risks of each, and when to use which.
- [What is Air-Gapped Signing?](https://coldcard.com/learn/hardware-wallets/air-gapped-signing): Air-gapped signing means the private keys never touch a device with a network connection at any point in the signing process. The unsigned transaction is passed to the signing device via QR code or physical media, the device signs it internally, and the signed transaction is returned the same way. Nothing travels over a network.
- [What is a Bitcoin Software Wallet?](https://coldcard.com/learn/hardware-wallets/bitcoin-software-wallet): A Bitcoin software wallet stores your keys on a phone or computer. Learn the types, what threats they face, and when a software wallet is and is not the right tool.
- [What is Bitcoin Multisig?](https://coldcard.com/learn/hardware-wallets/bitcoin-multisig): Multisig is a Bitcoin spending policy that requires signatures from more than one private key before a transaction can be authorized. No single key can move the funds on its own, so there is no single point of failure for theft or loss. A 2-of-3 multisig requires any two of three keys to sign.
- [2-of-3 Multisig Explained](https://coldcard.com/learn/hardware-wallets/2-of-3-multisig): A 2-of-3 multisig wallet requires any two of three keys to spend. Learn how to design a quorum, distribute keys, handle key loss, and why 2-of-3 is the most common multisig setup.
- [Collaborative Bitcoin Custody vs Solo Multisig](https://coldcard.com/learn/hardware-wallets/collaborative-custody-bitcoin): Collaborative custody gives a third party one key in your 2-of-3 wallet. Solo multisig means you hold all keys. Learn the tradeoffs: control, complexity, cost, and recovery.
- [What is a PSBT?](https://coldcard.com/learn/hardware-wallets/what-is-a-psbt): A PSBT is a standard format that separates transaction construction from signing. Learn how PSBTs work, why they matter for hardware wallets, and the difference between BIP174 and BIP370.
- [How to Store Your Seed Phrase](https://coldcard.com/learn/seed-phrases/how-to-store-seed-phrase): Storing a seed phrase correctly means writing every word in numbered order during wallet setup, choosing a durable physical medium, making at least two copies stored in geographically separate locations, and verifying recovery before you need it. Paper is adequate for a small spending wallet. A savings wallet requires a metal backup.
- [Paper vs Metal Seed Phrase Backups](https://coldcard.com/learn/seed-phrases/paper-vs-metal-seed-backup): Paper seed backups are free but burn and flood easily. Metal backups survive both. Learn why metal is better for savings wallets and what you need to know before choosing.
- [How to Choose a Metal Seed Backup](https://coldcard.com/learn/seed-phrases/metal-seed-backup): Metal seed backups record characters using three categories of approaches. Learn the criteria that matter and which method fits your setup.
- [Seed Phrase Storage and Physical Security](https://coldcard.com/learn/seed-phrases/seed-phrase-physical-security): Where you store your seed phrase backup is as important as what you store it on. Learn the physical threats to protect against and how to choose the right storage locations.
- [Bitcoin Inheritance Planning](https://coldcard.com/learn/seed-phrases/bitcoin-inheritance-planning): Bitcoin has no recovery path if keys are lost at death. Learn the four inheritance frameworks and how to choose the right one for your situation.
- [What is a Bitcoin Passphrase?](https://coldcard.com/learn/seed-phrases/bitcoin-passphrase): A Bitcoin passphrase is an optional word or phrase added to your seed phrase that creates an entirely separate wallet. Learn how it works, why it matters, and its risks.
- [Common Bitcoin Backup Mistakes](https://coldcard.com/learn/seed-phrases/bitcoin-backup-mistakes): Photographing your seed phrase, storing a single copy, or pairing a passphrase with a seed backup are mistakes that cost Bitcoin holders their funds. Learn what to avoid and why.
- [Bitcoin Transaction Security](https://coldcard.com/learn/transaction-security/bitcoin-transaction-security): Most self-custody attention goes to seed phrase storage. But every send involves a separate set of security decisions, from address verification to fee selection to how the transaction reaches the signing device.
- [What is Bitcoin UTXO Management?](https://coldcard.com/learn/transaction-security/bitcoin-utxo-management): Bitcoin has no account balance, only UTXOs. Learn what UTXOs are, why managing them affects fees and privacy, and how to manage them well.
- [Bitcoin Address Reuse and Management](https://coldcard.com/learn/transaction-security/bitcoin-address-reuse): Reusing a Bitcoin address links all your transactions permanently on-chain. Learn why address reuse hurts privacy and how HD wallets and coin control prevent it.
- [What is the Bitcoin Mempool?](https://coldcard.com/learn/transaction-security/bitcoin-mempool): The Bitcoin mempool holds unconfirmed transactions waiting for miners. Learn how it works, how to read mempool.space, and what to do when a transaction gets stuck.
- [What are Bitcoin Transaction Fees?](https://coldcard.com/learn/transaction-security/bitcoin-transaction-fees): Bitcoin fees are priced per virtual byte, not per transaction. Learn how sats/vbyte works, why SegWit addresses are cheaper, and how to set the right fee rate.
- [How to Verify Bitcoin Transactions](https://coldcard.com/learn/transaction-security/bitcoin-transaction-verification): On-device verification is the last line of defense before a Bitcoin transaction is signed. Learn how to check addresses, amounts, and fees on your signing device before every send, and how to confirm your transaction after broadcast.
- [What is Bitcoin Privacy?](https://coldcard.com/learn/bitcoin-privacy/bitcoin-privacy): Bitcoin transactions are public and permanently recorded on the blockchain. While addresses are pseudonymous rather than identity-linked by default, chain analysis firms trace fund flows using transaction patterns, address reuse, and UTXO relationships. Privacy requires deliberate practices at the network, transaction, and acquisition layers.
- [What is CoinJoin?](https://coldcard.com/learn/bitcoin-privacy/what-is-coinjoin): CoinJoin is a technique where multiple users combine their Bitcoin inputs into a single transaction with equal-value outputs, breaking the link between input and output. On-chain observers cannot determine which output belongs to which sender. Wasabi Wallet and JoinMarket are the main active implementations.
- [What is PayJoin?](https://coldcard.com/learn/bitcoin-privacy/what-is-payjoin): PayJoin is a two-party Bitcoin transaction where both the sender and receiver contribute inputs. Because the transaction does not follow the standard pattern, chain analysis change-detection heuristics fail. It requires no coordinator and produces no equal-value output set, making it harder to identify than CoinJoin.
- [Running a Bitcoin Node](https://coldcard.com/learn/bitcoin-privacy/run-bitcoin-node): Running a full Bitcoin node means verifying every transaction and block yourself, without relying on a third-party server. Wallet software connected to your own node does not expose your addresses or transaction history to external observers. For privacy, connecting Sparrow or another wallet to your own node is the correct baseline.
- [Using Tor with Bitcoin](https://coldcard.com/learn/bitcoin-privacy/tor-bitcoin): Tor routes Bitcoin network traffic through a series of relays to hide your IP address from peers, analytics firms, and network observers. Bitcoin Core can be configured to broadcast transactions over Tor. Connecting Sparrow Wallet to a Bitcoin node via .onion address prevents your wallet queries from being linked to your IP.
- [What are Bitcoin Improvement Proposals (BIPs)?](https://coldcard.com/learn/advanced-concepts/bitcoin-improvement-proposals): A Bitcoin Improvement Proposal (BIP) is a formal document that proposes a change or standardization to the Bitcoin protocol or related tooling. BIPs go through a review and adoption process before becoming active standards. Most of the wallet infrastructure used today, including seed phrases and HD key derivation, is defined by specific BIPs.
- [The Most Important BIPs](https://coldcard.com/learn/advanced-concepts/key-bitcoin-bips): BIP32 defined hierarchical deterministic key derivation. BIP39 defined seed phrases as the human-readable encoding of a master seed. BIP174 defined the PSBT format for separating transaction construction from signing. BIP341 implemented Taproot, enabling more efficient and private transaction scripts. Together, these four proposals define most of how modern Bitcoin wallets function.
- [Bitcoin Air-Gap Signing Methods](https://coldcard.com/learn/advanced-concepts/air-gap-signing-methods): BBQr, MicroSD, and NFC are the three methods used to carry PSBTs across the air gap between wallet software and a signing device. BBQr encodes transaction data as a sequence of animated QR codes for large payloads. MicroSD transfers the file physically. NFC passes data wirelessly over short range without a network connection.
- [What are Bitcoin Forks?](https://coldcard.com/learn/advanced-concepts/bitcoin-forks): A fork is a change to Bitcoin's consensus rules. Soft forks tighten existing rules and are backward-compatible. Hard forks introduce incompatible rule changes that can split the network into two separate chains. If you hold your own private keys through a hard fork, you hold coins on both chains.


## Guides
- [Guides](https://coldcard.com/guides/)
- [Get Started with Bitcoin Self-Custody](https://coldcard.com/guides/getting-started/bitcoin-self-custody-guide): A complete overview of taking bitcoin self-custody with Coldcard: verifying your hardware, initializing the device, securing your seed phrase backup, and connecting Sparrow Wallet as coordinator. Covers both Q and Mk5.
- [Set Up Your Coldcard Q](https://coldcard.com/guides/setup/coldcard-q-setup): Step-by-step setup for Coldcard Q: tamper-evident bag inspection, PIN creation with anti-phishing words, seed phrase generation using hardware random number generators, and backup quiz. Verified against firmware v1.4.0Q.
- [Set Up Your Coldcard Mk5](https://coldcard.com/guides/setup/coldcard-mk5-setup): Step-by-step setup for Coldcard Mk5: tamper-evident bag inspection, PIN creation with anti-phishing words, seed phrase generation using hardware random number generators, and backup quiz. Verified against firmware v5.5.0.
- [Coldcard and Sparrow Wallet Setup](https://coldcard.com/guides/wallets/coldcard-sparrow-wallet-setup): Export a Coldcard wallet descriptor to Sparrow Wallet as a watch-only setup. Covers the recommended MicroSD/QR export path, the optional USB-connected path, the import steps in Sparrow, and the address verification required before receiving funds. Covers Q and Mk5.
- [Build a 2-of-3 Multisig Vault with Coldcard](https://coldcard.com/guides/advanced/coldcard-multisig-setup): Build a 2-of-3 multisig vault with three Coldcard devices, using Create Airgapped to assemble the wallet on-device and Sparrow Wallet as the watch-only coordinator. Covers xpub export, wallet creation, config distribution, address verification across all devices, and a test signing round before depositing funds.
- [QR Code Air-Gapped Signing with Coldcard](https://coldcard.com/guides/using-coldcard/coldcard-qr-signing): How to sign Bitcoin transactions with Coldcard Q using QR codes and BBQr. Covers transaction creation in Sparrow, on-device address verification, signing, and broadcasting. Verified against v1.4.0Q.
- [How to Secure Your Trezor with COLDCARD](https://coldcard.com/guides/secure-trezor-with-coldcard): Use COLDCARD BIP-85 to create a dedicated Trezor seed, isolate stablecoins and other assets, and verify multi-network recovery before funding.
- [How to Secure Your Jade with COLDCARD](https://coldcard.com/guides/wallets/secure-jade-with-coldcard): Use COLDCARD BIP-85 to create a dedicated Jade seed, isolate Bitcoin or Liquid assets, and verify reproducible recovery before funding the wallet.
- [How to Secure Your SeedSigner with COLDCARD](https://coldcard.com/guides/wallets/secure-seedsigner-with-coldcard): Use COLDCARD BIP-85 to create a dedicated SeedSigner seed, preserve stateless QR operation, and verify recovery before funding a live wallet.
- [How to Secure Your Keystone with COLDCARD](https://coldcard.com/guides/wallets/secure-keystone-with-coldcard): Use COLDCARD BIP-85 to create a dedicated Keystone seed, isolate multi-chain assets, and preserve the cross-chain metadata needed for recovery.
- [How to Secure Your Ledger with COLDCARD](https://coldcard.com/guides/wallets/secure-ledger-with-coldcard): Use COLDCARD BIP-85 to create a dedicated Ledger seed, isolate stablecoins and other assets across networks, and verify recovery before funding.
- [How to Secure Your Tangem with COLDCARD](https://coldcard.com/guides/wallets/secure-tangem-with-coldcard): Use COLDCARD BIP-85 to create a dedicated Tangem seed, isolate stablecoins and other networks, and preserve the metadata needed for recovery.
- [NFC Tap Air-Gapped Signing with Coldcard](https://coldcard.com/guides/using-coldcard/coldcard-nfc-signing): How to sign Bitcoin transactions with Coldcard using NFC tap, sending and receiving a PSBT between Coldcard and a mobile wallet with no cable, camera, or MicroSD card.
- [MicroSD Card Air-Gapped Signing with Coldcard](https://coldcard.com/guides/using-coldcard/coldcard-microsd-signing): How to sign Bitcoin transactions with Coldcard using a MicroSD card. Covers the full round trip with Sparrow Wallet on Coldcard Q and Mk5, from transaction creation to broadcast.