What is Trezor Bridge?
Trezor Bridge is a small background application created by the makers of Trezor that facilitates communication between your Trezor hardware wallet (the physical device) and browser-based wallet interfaces (like Trezor Suite or compatible web wallets). It replaces the older browser-based interaction layers and serves as a secure, local bridge translating USB/HID device protocols into a form the browser can use.
Why Bridge exists (short)
Modern browsers restrict direct hardware access for security reasons. Trezor Bridge provides a controlled, signed connector that sits on your machine and exposes a local API endpoint. That means website code never talks directly to the USB device — instead it talks to the Bridge which enforces origin checks and the Trezor signing flow.
Installing Trezor Bridge (practical steps)
- Download from Trezor's official site or your domain's canonical mirror. Always verify the domain and certificate. Example:
https://your-domain.example/trezor-bridge. - Run the installer for your OS (Windows .exe, macOS .dmg, Linux .deb/.AppImage). On macOS Big Sur+ you may need to allow the loader in System Preferences → Security & Privacy.
- After installation, Bridge runs as a small background service and exposes a local address like
http://127.0.0.1:21325. Trezor Suite or the web wallet will detect it automatically.
/Library.
Security considerations
Installing Bridge itself is low-risk when downloaded from the official source. Key security points:
- Origin protection: Bridge only accepts requests from authorized origins. Malicious websites cannot directly cause transactions without user confirmation on-device.
- Local-only: The Bridge server listens on localhost by design. If you ever see Bridge listening on non-local network interfaces, treat it as suspicious and investigate.
- Check signatures: Where available, verify the installer signature or checksums. This prevents tampered packages from being installed.
Troubleshooting common issues
If your device isn't detected, go through these steps in order:
- Make sure the device is unlocked and the screen is on.
- Confirm Bridge is running: on Windows check Services or tray icon; on macOS check the menu bar or Activity Monitor.
- Try a different USB cable (not a charge-only cable) and port; avoid USB hubs during initial troubleshooting.
- Temporarily disable third-party antivirus/USB-monitoring software that can block Bridge's runtime.
- Reinstall Bridge and restart the browser. For Trezor Suite, try restarting the app.
If the problem persists, collect logs and consult official support channels; do not provide your seed or PIN to anyone.
Best practices while using Bridge
Treat your hardware wallet as the root of trust:
- Only confirm transactions on the device screen — always read recipient and amount.
- Keep your firmware and Bridge updated from official releases; updates often include security hardening.
- Use Bridge with well-known wallet software. Avoid experimental browser extensions unless you understand the risks.
- When not using the device, unplug it. On shared machines, be especially cautious about background services.
Advanced: When to prefer Trezor Suite
Trezor Suite is the official desktop app that bundles a user interface with embedded Bridge functionality. If you want fewer moving parts (no separate browser + Bridge combination), using Trezor Suite reduces the number of software components and can simplify updates — but both approaches are secure when kept current.
Conclusion — keep Bridge minimal and monitored
Trezor Bridge is a small, focused helper: it solves a modern browser-hardware access problem while keeping the security-critical actions on your physical device. The essentials are simple — install only from trusted sources, keep everything updated, and confirm actions on the device. With those habits, Bridge adds convenience without sacrificing the hardware wallet’s security model.