H3: What is Trezor Bridge?
Trezor Bridge is a small desktop application that enables communication between your web browser (or other desktop apps) and a Trezor hardware wallet. It acts as a local intermediary, translating requests from web interfaces—such as Trezor Suite or compatible web wallets—into a USB protocol the device understands. Unlike browser-native USB access (which is limited or sandboxed), Bridge offers a stable, cross-platform way to connect Trezor devices on Windows, macOS and Linux.
Browser environments and operating systems impose safety restrictions on how websites access USB-connected devices. Bridge provides a user-focused solution that balances security and usability: it permits trusted applications to talk to the Trezor hardware without exposing the device to arbitrary web pages. This reduces attack surface and makes the user experience reliable across different system configurations.
The Bridge runs as a local service. When installed it listens on a local port and accepts signed, encrypted RPC-style calls from local web pages (or apps). These calls are validated and forwarded to the hardware device via the native USB stack. Responses are relayed back in the same way. This lightweight architecture keeps the logic off the device (so firmware remains compact) while keeping the device in physical control of critical signing operations.
Bridge typically supports Windows, macOS and common Linux distributions. Each platform uses a slightly different installation and permission model; the Bridge installer handles the specifics.
Have your Trezor device at hand and ensure you're downloading Bridge only from official channels (see the 10 links above). Close other wallet apps and temporarily disable aggressive browser extensions that may block local connections.
Confirm Bridge is running by checking your system tray (Windows/macOS) or by opening the downloads page again; the web UI should show 'Bridge connected'. You can also try a simple device query in Trezor Suite to see if the device fingerprint appears.
For most users the steps are straightforward: connect device → open Suite or web wallet → authenticate on-device. Bridge handles the low-level communication so you can focus on confirmations and device checks on the Trezor screen.
Restart the Bridge service and try reconnecting the device. On Windows check Device Manager for missing drivers; on macOS ensure security settings didn't block the installer.
Confirm no firewall or privacy extension is blocking local loopback connections. Try an alternate browser or disable extensions temporarily. If using a sandboxed browser build, prefer connecting through the officially supported Suite app.
Read the message on the device display carefully. Many errors are caused by low-level USB problems or interrupted firmware transfers. If firmware update fails, consult the official support guides before retrying.
Trezor Bridge is designed assuming the host OS and browser may be compromised. The security model places critical secrets on the hardware device — private keys never leave the device — and uses Bridge only to relay instructions. Users must still protect their host environment: untrusted software, keyloggers, or malicious browser extensions can still trick or alter transaction details before they reach the device for signing.
Bridge facilitates device connection but does not transmit identifying user data to servers by itself. The web clients you use (wallets, Suite) may communicate with external services for price data or blockchain queries; review those services' privacy policies if that matters to you.
Developers building wallet integrations can use the official libraries and transport layers that talk to Bridge. Typical integrations involve:
// Example (pseudocode) showing a transport call
const transport = await BridgeTransport.create();
const info = await transport.call({type: 'getPublicKey', path: "m/44'/0'/0'/0/0"});
console.log('account:', info.publicKey);
Ensure your integration handles user rejections, device disconnects, and slow connections. Tests should include: simulated USB interrupts, firmware version mismatches, and multi-account scenarios.
An everyday user uses Bridge to connect Trezor Suite and manage crypto holdings. Typical flows are account setup, receiving funds, sending transactions, and firmware updates.
Power users might integrate Bridge into scripts or alternative clients for advanced signing workflows, multisig coordination, or hardware-backed developer tools.
No. Bridge only relays encrypted commands; the seed and private keys remain on the Trezor device and are never transmitted to the host or network.
Some platforms and advanced setups may use native WebUSB or alternative transports, but Bridge is the recommended cross-platform solution for stability and compatibility.
Consult the official developers' page and repository listings for source code and licensing details — transparency is a cornerstone of the Trezor project.
Regularly update Bridge, Trezor Suite and device firmware. When prompted to update firmware, verify release notes from official sources and follow instructions carefully.
Record your recovery seed securely and offline. Bridge does not manage or store recovery seeds — its role is strictly a transport layer. If your device is lost or replaced, the seed is the only reliable recovery path.
Trezor Bridge provides a secure, cross-platform bridge (pun intended) between desktop clients and the hardware wallet. Its design keeps private keys secured on the device while offering a smooth, reliable experience for signing and device management. For most users the combination of Bridge + Trezor Suite offers the best balance of security and convenience; developers and power users can extend this foundation into custom workflows while following the security recommendations above.
Use the official links at the top of this document to reach authoritative guides, downloads, and support resources. Refer to the Developers and Firmware pages for integration and update details.