What is Trezor Bridge?
Overview
Trezor Bridge is the small helper application that allows a Trezor hardware wallet to communicate with a web browser or desktop applications over USB. Think of it as the bridge between your browser (or desktop wallet) and the secure hardware that stores your private keys. It handles device discovery, secure messaging, and keeps the browser sandbox from having to talk directly to USB devices.
Why it matters
Hardware wallets like Trezor are designed so your private keys never leave the device. The Bridge provides a reliable, cross-platform channel so your browser-based wallet interfaces (like web apps) can request signatures, read addresses, and manage accounts without exposing secret material to the host. This separation improves security, reduces complexity in the browser, and makes device compatibility smoother.
Key responsibilities
- Device detection and connection management (USB)
- Forwarding JSON-RPC requests to the hardware in an isolated process
- Permitting user confirmation flows when a signature or sensitive action is requested
How it works (high level)
When a web wallet wants to use your Trezor, it attempts to reach the Bridge using a local endpoint. The Bridge runs on your machine and exposes a local HTTP/HTTPS interface. The web app sends a request to that interface, the Bridge translates the request to the Trezor communication protocol, asks the device to process it, and then passes the response back to the web app.
Installation & setup
Installing the Bridge is straightforward: download the official installer for your operating system, run the installer, and keep the Bridge running while using web wallets. Many modern Trezor-compatible web apps will prompt you when the Bridge is missing and provide a download link.
Typical steps:
- Download from the official source (always verify the domain you're using).
- Run installer and follow platform prompts (macOS, Windows, Linux packages are available).
- Plug in your Trezor device and confirm any on-device prompts.
Security considerations
Bridge is intentionally minimal: it only facilitates communication and does not hold private keys. However, follow basic safety practices:
- Download Bridge only from official or trusted sources.
- Keep the application updated to receive security and compatibility fixes.
- Only approve actions on your Trezor device that you initiated and understand.
- Use a secure, up-to-date browser when using web-based wallets.
Troubleshooting tips
Connection problems are usually straightforward to fix:
- No device found: Check cable and port; try another USB port or cable.
- Bridge not running: Launch the Bridge app manually or reinstall it.
- Browser blocking connection: Ensure the web app uses allowed localhost endpoints and your OS firewall isn't blocking it.
- Device asks to reset unexpectedly: Never confirm a reset unless you initiated it — this could indicate a malicious action.
FAQ — quick answers
Do I need Bridge for mobile? Many mobile apps use alternative transports (like WebUSB or native integration). Bridge is primarily for desktop browsers and apps.
Is Bridge open source? Components related to Trezor are frequently open source, but always check the project's repository or documentation for current licensing and code availability.
Final notes
Trezor Bridge is a small but essential piece of the hardware-wallet ecosystem: it keeps the communication channel secure and predictable while letting web apps focus on user experience. If you're setting up a Trezor, make it a habit to verify downloads, keep software updated, and rely on on-device confirmations for any critical action — the device itself is the ultimate authority.
Learn more / official downloads