Trezor Bridge — simple explanation, secure setup, and practical tips
What is Trezor Bridge?
Trezor Bridge is a small, user-level application that lets web browsers and desktop apps communicate with a Trezor hardware wallet. When you plug a Trezor into your computer, Bridge acts as the intermediary that translates browser requests (from sites like wallet interfaces) into commands the device understands, and returns signed responses to the browser.
Think of it as a translator and gatekeeper: it provides a secure channel between your device's USB port and the web UI while keeping the hardware wallet isolated from direct, unrestricted access by random programs.
Why Bridge exists (short technical background)
Browsers restrict direct access to raw USB for security and compatibility reasons. Historically, wallet manufacturers used browser extensions to bridge this gap; Bridge replaces that model with a small native app that uses secure local APIs. This approach improves cross-platform compatibility and reduces the risks that come with browser extensions or poorly configured web USB access.
How it works (practical view)
When you open a Trezor-compatible website:
- The website asks the browser to talk to the Bridge.
- Bridge receives the request and forwards it to the Trezor device over USB (or WebUSB where supported).
- The device displays a confirmation on its screen; you confirm directly on the hardware.
- Signed transactions or requested data are returned via Bridge to the website — the private keys never leave the device.
Because you must confirm actions on the physical device, remote attackers cannot trigger transactions without access to your hardware wallet's buttons (or screen, depending on model).
Installing and updating
Installation is straightforward: download the official Bridge installer for your operating system and run it. On macOS and Windows, it installs a tiny background service and a minimal UI. Linux distributions often require a package or a simple script to set up the udev rules and service.
Safety tip: always download Bridge from the official Trezor website. Do not install copies from random mirrors or third-party sites. Check file signatures if you want extra assurance.
Common troubleshooting
- Device not detected: try a different USB cable or port; some cables are power-only and won't transmit data.
- Browser can't connect: ensure Bridge is running and not blocked by firewall software. Restart the browser after installing Bridge.
- Permission prompts: accept prompts in the browser when asked to allow the website to connect. If you previously blocked a site, clear the browser's site permissions for USB devices.
- Bridge update required: if a wallet UI prompts for a Bridge update, install it — updates fix compatibility and security issues.
Security best practices
Trezor Bridge is designed to minimize attack surface, but your setup matters:
- Install Bridge only from the official Trezor domain.
- Keep your Trezor firmware and Bridge app up to date.
- Use strong, unique passwords for any accounts associated with your wallet (email, exchange accounts, metadata providers).
- Never enter your recovery seed into a computer or smartphone. The seed belongs only on paper or metal backup, stored offline.
- When prompted to confirm actions, always verify transaction details on the device screen — not just in the browser UI.
Privacy and network considerations
Bridge only facilitates local communication; it does not leak your private keys or transaction secrets. However, the wallet interface you use may request external data (like account balances or network fees) from public API providers. If privacy matters, consider running your own node or using privacy-focused explorers with the wallet’s settings.
Alternatives and when to use them
If you prefer not to run Bridge, some Trezor-compatible apps support direct WebUSB connections or mobile pairing options that work with companion apps. Those alternatives trade convenience for different trust boundaries — read their documentation and choose based on your threat model.
Quick checklist before making a transaction
- Bridge is running and up to date.
- Your Trezor firmware is up to date and the device boots normally.
- Confirm the receiving address on the device screen before approving.
- Use a known, trusted wallet UI — bookmark it rather than following search results.
FAQ — short answers
Do I need Bridge for every OS? Usually yes for desktop OSes; some browsers and platforms provide direct USB options, but Bridge remains the most reliable cross-platform solution.
Is Bridge open source? Parts of the Trezor toolchain are open source. If open-source status matters to you, check the Trezor GitHub repositories for the latest project details.
Will Bridge ever access my recovery seed? No. Bridge only handles communication; it never needs the recovery seed. The seed is only used on the device during setup or recovery.