USBSparrow · BitcoinMk5 set up and unlocked · verified current firmware · USB data enabled · data cable
Ledger Flex:
✓
USBLedger Wallet · Bitcoin / Ethereum
Set up the wallet
Coinkite COLDCARD Mk5:
✓
microSDSparrow · Bitcoin
✓
USBSparrow · BitcoinMk5 set up and unlocked · verified current firmware · USB data enabled · data cable
Ledger Flex:
✓
USBLedger Wallet · Bitcoin / Ethereum
Approve transactions
iPhone
Coinkite COLDCARD Mk5:
✓
NFCNunchuk · Bitcoin
iPhone · Nunchuk · NFC · BitcoinSupport for wallet setup is unconfirmed
Ledger Flex:
✓
BluetoothLedger Wallet · Bitcoin / Ethereum
Android
Coinkite COLDCARD Mk5:
✓
NFCNunchuk · Bitcoin
Android · Nunchuk · NFC · BitcoinSupport for wallet setup is unconfirmed
Ledger Flex:
✓
USB · BluetoothLedger Wallet · Bitcoin / Ethereum
Where they differ
Cryptocurrencies
Coinkite COLDCARD Mk5:Bitcoin-only
Ledger Flex:Multiple cryptocurrencies
Controls / Display
Coinkite COLDCARD Mk5:Physical buttonsDisplay: Display without touch input
Ledger Flex:Touchscreen
Battery
Coinkite COLDCARD Mk5:No battery
Ledger Flex:Rechargeable
What they have in common
Wallet recovery
Recovery phrase
Both
Not fully confirmed
Operating power
Coinkite COLDCARD Mk5:USB power
Ledger Flex:Not recorded
Before you choose
Consider
Coinkite COLDCARD Mk5Needs USB-C power during use. Check the current seed-generation advisory before reusing an older wallet; updating alone does not repair an affected seed.
Ledger FlexiPhone connects by Bluetooth. Android connects by USB or Bluetooth. NFC does not replace USB or Bluetooth for ordinary transactions. Cryptocurrency support depends on the app.
Sparrow exchanges unsigned and signed Bitcoin transaction files (PSBTs) with Mk5 through microSD. Your computer needs a compatible card reader.
SparrowUSBBitcoinWindows · macOS · LinuxMk5 set up and unlocked · verified current firmware · USB data enabled · data cableConnection requirements
Start with a Mk5 already initialized under its setup guide, running the verified current recommended standard firmware. Keep Mk5 unlocked, enable USB data and use a data-capable USB-C cable. Then add its wallet to Sparrow and sign Bitcoin transactions over USB.
iPhone · Android
NunchukNFCBitcoinSupport for wallet setup is unconfirmedConnection requirements
Use Nunchuk on a compatible NFC phone with an already initialized Mk5, powered on and with NFC enabled. Import the wallet’s public account into Nunchuk before exchanging Bitcoin transaction files (PSBTs).
Ledger Flex
Computer
Ledger WalletUSBBitcoin / EthereumWindows · macOS · Linux