Official Guide

Trezor Bridge — The Secure Gateway to Your Hardware Wallet®

A complete explanation of Trezor Bridge: what it does, how to install and use it, its security model, troubleshooting, and best practices for securely connecting your Trezor device to desktop and web applications.

Install Bridge

What is Trezor Bridge?

Trezor Bridge is a small local application that enables secure communication between your Trezor hardware wallet and host applications running in your browser or on your desktop. It acts as a mediating service that translates web requests into USB commands the device understands, and vice versa. Bridge is specifically designed to preserve the hardware wallet’s security model: private keys and sensitive signing operations stay on the Trezor device, while only unsigned transaction data and non-sensitive metadata are exchanged via the host.

Why Bridge Exists

Browsers impose security constraints that limit direct USB access for web pages. Trezor Bridge provides a secure, user-controlled local endpoint so browser-based wallet apps can interact with the device without compromising safety or requiring elevated system privileges. Bridge supports cross-platform usage and helps standardize communication between multiple host environments and Trezor devices, simplifying user experience while keeping cryptographic operations isolated on the device itself.

How Trezor Bridge Works

  1. Local service: After installation, Bridge runs as a background service that listens on a local port (or uses platform-specific IPC mechanisms) for requests from browser tabs or desktop apps.
  2. Request translation: When a wallet application needs to query accounts or prepare a transaction, it sends a JSON-RPC (or similar) request to the local Bridge endpoint. Bridge translates these into the USB protocol understood by the device and forwards them securely.
  3. On-device verification: The Trezor device displays transaction details and requires physical user confirmation for signing. The signed transaction is returned through Bridge to the host app for broadcasting to the network.
  4. User control: At no point does Bridge expose private keys; it only transports encoded messages and ensures they reach the device. The final user confirmation on the physical device is always the authoritative action.

Installing Trezor Bridge

Installation is straightforward and available for Windows, macOS and Linux. Always download Bridge from the official Trezor website to avoid malicious or tampered installers.

  1. Visit the official Trezor download page and choose the Bridge installer matching your operating system.
  2. Run the installer and follow on-screen instructions. Administrative privileges may be required on some platforms.
  3. After installation, Bridge typically starts automatically and will display a tray or menu bar icon depending on your platform.
  4. Open your preferred Trezor-compatible web wallet or desktop Suite; the app should detect Bridge and prompt you to connect your device.
Tip: If an existing application can't find Bridge, try restarting your browser or the host app, and confirm Bridge is running in your system tray or taskbar.

Permissions & Privacy

Bridge intentionally minimizes permissions and does not collect or transmit private wallet data to external servers. Its primary function is to forward locally generated requests. Bridge does not require internet access to function for most operations; only when host apps need to fetch checkpoints, block explorers, or price data will external network requests occur, and those are handled by the host application — not Bridge.

Security Model

The security model of Trezor Bridge rests on three pillars: hardware‑based key isolation, explicit user confirmation, and a trusted local transport. Private keys remain on the Trezor device at all times; Bridge cannot extract them. All operations that alter private key state (signing transactions, revealing sensitive keys) require the user’s action on the device screen. Bridge simply delivers the messages between the device and host and helps verify the authenticity of firmware updates when used alongside official Suite tools.

For the strongest security, always confirm details on the physical device screen and keep Bridge and host applications up to date.

Browser Integration & Security Considerations

Modern browsers implement strict cross-origin and permission models. Trezor-compatible web wallets typically request explicit permission to access the local Bridge endpoint; browsers may prompt you to confirm such access or to allow pop-ups. Do not ignore unexpected browser prompts that request access to Bridge — always verify the requesting site’s authenticity before granting permission. Bookmark trusted wallet sites and avoid entering sensitive information on sites you don’t control.

Updates & Maintenance

Keep Trezor Bridge updated to benefit from security fixes and compatibility improvements. Updates are released by Trezor and should be installed from the official download sources. On some platforms, Bridge can update automatically or notify you when updates are available. After updating, restart your browser and re-open any web apps that use the service to ensure proper reconnection.

Troubleshooting

Device Not Detected

If your Trezor device is not detected, try the following steps:

  • Confirm Bridge is running in your system tray or taskbar.
  • Try a different USB cable or port; use a data-capable cable (some cables are power-only).
  • Restart Bridge, your browser, and the host application.
  • On Windows, ensure device drivers are installed; on macOS, confirm system permissions allow USB access.

Connection Errors & Timeouts

Bridge may report a local connection error if another process is blocking the port or if permissions are insufficient. Close conflicting applications that might access USB devices (such as other wallet apps), and check firewall settings that could interfere with local communications.

Best Practices

  • Download Bridge only from the official Trezor site and verify installer integrity when available.
  • Keep Bridge and your browser up to date to receive security patches and compatibility fixes.
  • Use a trusted host machine for signing high-value transactions and consider a dedicated device for critical operations.
  • Always confirm transaction details on the Trezor device screen before approving — the device’s display is the final authority.
  • Disable Bridge when not in use if you prefer extra control over local services; you can start it manually when needed.

Developer Notes & Integration

Developers integrating Trezor support into web or desktop wallets should follow official SDKs and API patterns. Bridge exposes a local API surface that client libraries can call to perform device discovery, get public keys, and request signatures. When building integrations, design clear UI flows that prompt users to verify actions on the physical device, and never request seeds or private material through the host. Respect CORS and same-origin policies and implement robust error handling when Bridge is unavailable.

Frequently Asked Questions

Do I need Bridge to use my Trezor?

For many browser-based wallets and the official Suite web app, Bridge is required to enable secure local communication. Some desktop Suite applications include native USB support and may not require Bridge. Check the specific application's documentation to confirm.

Is Bridge safe to run on my computer?

Yes — Bridge is a minimal local service designed to forward messages between host apps and the device. It does not store private keys, and when downloaded from official sources it is safe to run. Maintain good host hygiene by using updated OS software and avoiding untrusted applications.

Can Bridge be used remotely?

No. Bridge is intended as a local-only intermediary. Exposing it over a network would create significant security risks; do not forward Bridge ports over the internet or run it on an untrusted network-facing host.