What is Trezor Bridge?
Trezor Bridge is the official client that allows browsers and desktop applications to detect and communicate with your Trezor device. It acts as a local intermediary: the application sends unsigned transactions or commands to Bridge, Bridge forwards them to the hardware device over USB, and the device returns signed responses after you confirm them on the device screen. This architecture prevents direct access to the device by remote servers and ensures the critical signing step happens physically on the Trezor unit.
Why you should use Bridge
Many modern browsers restrict direct USB access for security reasons. Bridge solves this by providing a secure, user‑approved channel that works across platforms — Windows, macOS and Linux. It improves compatibility with web apps that need to interact with hardware wallets and simplifies the developer experience, while still preserving the hardware security model.
Install & Verify
Download Bridge from the official Trezor downloads page. Choose the installer matching your OS and follow the prompts. On macOS you may be asked to approve a kernel extension or security permission — follow the official instructions. After installation, restart your browser or application and connect your Trezor. Verify you’re using an official installer by checking the download URL and, where available, the digital signature or checksum.
How Bridge Works — a short technical primer
Bridge listens on a local port and provides a limited API that applications use to forward commands. It translates these into USB HID or WebUSB messages understood by the Trezor device. Importantly, Bridge does not persist private keys, seeds, or passphrases. It simply forwards messages between the app and device and enforces access control so only permitted applications can reach the device while it is unlocked.
Security Considerations
Trezor’s security model places the signing authority on the hardware device. Bridge respects this by never exposing signing capabilities to remote services. However, you should still follow standard precautions: install Bridge only from official sources, keep Bridge updated, and run trusted applications. Remember that a compromised computer could attempt to trick you by showing altered transaction data on-screen; always verify addresses and amounts on your Trezor device itself before approving.
Troubleshooting
If your device is not recognized, try these steps: disconnect and reconnect your device, reboot your computer, ensure Bridge is running (check system tray or background services), and try a different USB cable/port. On some OS versions, browser permissions or security settings may block Bridge — consult the official troubleshooting guide for specific diagnostics. Reinstalling Bridge and restarting the browser often resolves common connectivity problems.
Updates & Maintenance
Keep Bridge and Trezor Suite up to date. Updates include security fixes and compatibility improvements with new browsers and operating systems. Bridge updates are released through the official downloads page. For systems with strict IT policies, coordinate with your administrator before installing user‑level drivers or helpers.
For Developers
Developers can integrate with Bridge using the published API. The architecture allows building web-based wallet interfaces that interoperate with Trezor devices without direct USB access in unsupported browsers. Review the developer documentation, follow recommended security patterns, and ensure your web app requests only the permissions it needs. Testing against the emulator and real hardware is recommended before production deployment.
Best Practices
Always verify the origin of the web app you connect to, keep your OS and browser updated, and use device verification prompts on the Trezor screen before confirming transactions. For high-risk operations, consider using a dedicated machine or sandboxed environment to reduce exposure. If you are using Bridge in a corporate environment, follow IT guidelines to manage software updates and permissions centrally.