Your Offline Wallet, Now Has a Watchful Eye

    COLDCARD Companion is a secure browser interface that keeps your keys offline while giving you full visibility and transaction control.

    Compatible With:

    Chrome
    Brave
    Firefox

    Extension Features

    Track Bitcoin Holdings

    Monitor your Bitcoin balances via watch-only xpub while keeping your keys offline and secure.

    Build PSBT Transactions

    Create unsigned transaction files that can be safely transferred to your COLDCARD for signing.

    View Balances with USD

    See your Bitcoin holdings with real-time USD conversions for better financial visibility.

    Broadcast Signed Transactions

    Easily broadcast your signed transactions to the Bitcoin network directly from your browser.

    Verify Receiving Addresses

    Ensure address integrity by verifying receiving addresses between your wallet and extension.

    Multiple Connection Options

    Compatible with QR codes, MicroSD cards, and USB for flexible interaction with your COLDCARD.

    Interface Preview

    Total Balance

    0.25 BTC≈ $26,630.05

    Recent Transactions

    Received+0.05 BTC
    Sent-0.02 BTC

    Addresses

    Receivebc1q...7d4f
    Changebc1q...2a9e

    Security Reminder

    This extension does not store or access your private keys. All transactions must be signed offline using your COLDCARD hardware wallet.