What is Trezor Bridge?
Trezor Bridge is a small helper program that runs on your computer and provides a local API for browsers and applications to talk with your Trezor device. Because modern browsers restrict direct access to USB devices for security reasons, Bridge provides a secure and user-accepted path for the browser to send commands to the device.
How it works (simple)
When installed, Bridge listens on localhost and exposes a controlled endpoint that Trezor Suite or compatible web wallets can call. When you plug in your Trezor, the browser issues a request which Bridge mediates — the device never leaves your hands, and private keys remain on-device. Bridge only facilitates the connection, not the signing or exposure of sensitive data.
Key features
Installation & first run
Download the official Bridge installer from Trezor's website (always verify the domain and signatures). Choose the package for your OS, run the installer, and follow the on-screen steps. After installation, Bridge runs in the background — you may see a small tray icon or menu bar item depending on your operating system.
Troubleshooting
If your browser can’t detect the device, try the following:
- Make sure Bridge is running (check system tray / Activity Monitor).
- Replug the USB cable and use the original cable provided with your Trezor — avoid USB hubs when possible.
- Restart the browser after installing Bridge; some browsers need a restart to update permissions.
- Temporarily allow the site in your browser when prompted (the browser will ask for permission to access Trezor via Bridge).
Advanced: run trezorctl enumerate (or the debug tool included with the Bridge package) to check whether the OS recognizes the hardware.
Security considerations
Trezor Bridge is designed to minimize attack surface. It does not have access to your seed phrase or private keys. Only signed messages and commands necessary for wallet operations travel through the Bridge to the device. Still, follow these best practices:
- Download Bridge only from official sources and verify checksums/signatures when provided.
- Keep your OS and browser up to date to benefit from the latest security patches.
- Use strong passwords and two-factor authentication for the services you connect to via Trezor Suite.
Developer notes
If you are building an app that integrates with Trezor devices, the recommended approach is to use the Trezor Connect library which will automatically detect Bridge. Bridge exposes a local HTTP interface; developers should never request more permissions than necessary and must always request user consent before interacting with the device.
FAQ
- Do I need Bridge if I use Trezor Suite?
- Yes, Bridge or a supported native driver is required so the application can communicate with the device.
- Is Bridge open source?
- Parts of the Trezor ecosystem are open source. Check the official Trezor GitHub repositories for code, build instructions, and release artifacts.
- Can I use Bluetooth?
- Trezor devices do not use Bluetooth for security reasons. Communication is designed over USB (or USB-C) via Bridge.