Trezor Bridge acts as a local messenger between your Trezor hardware wallet and cryptocurrency apps on your computer. It enables secure USB communication where native WebUSB is not available or when additional integration is required.

Last updated: 2025

What is Trezor Bridge?

Trezor Bridge is a small local application (a background process) that runs on your computer and provides a stable, secure bridge between web-based wallet interfaces (or desktop apps) and your Trezor hardware device. When installed, it listens on a local port and presents a trusted API that authorized browser sessions or applications can use to communicate with the device without exposing it directly to the network.

Why use Trezor Bridge?

  • Compatibility: Works with browsers or platforms that lack sufficient WebUSB support.
  • Stability: Provides consistent device access across different OS and browser configurations.
  • Signed and verified: Official Trezor Bridge builds are cryptographically signed to ensure integrity.
  • User experience: Simplifies connectivity by handling low-level USB details in the background.

Install & setup (step-by-step)

1

Download from official source

Always download Trezor Bridge from the official website or the official Trezor download page. Avoid third-party mirrors. Verify checksums when provided.

2

Choose the right package

Bridge is available for Windows, macOS, and Linux. Select the installer that matches your operating system and architecture (x64, ARM when supported).

3

Run the installer

Follow the installer prompts. On Windows, you may need administrator privileges. The installer sets up a background service/agent so the Bridge starts automatically when you log in.

4

Allow firewall access (if prompted)

Because Bridge listens on a local port, some firewall tools may prompt you to allow it. Allow only local loopback connections — Bridge does not accept remote network connections by default.

5

Connect your Trezor device

Use a high-quality USB cable and plug your device into the computer. Open your preferred wallet interface (for example, Trezor Suite or a supported browser plugin) and follow the on-screen connection prompts.

6

Confirm device requests on the Trezor screen

The physical device will always show transaction details and prompts that must be confirmed on its screen — that confirmation is the final authority for all operations.

Security considerations for Trezor Bridge

Security is paramount. Trezor Bridge is designed to minimize attack surface by limiting exposure to local machine processes and using signed releases. Still, you should follow these practices:

  • Install only official releases from the vendor and verify signatures/checksums when available.
  • Keep your OS and Bridge up to date to receive security patches.
  • Restrict Bridge to local loopback access; do not forward Bridge ports over the network or expose them to remote access.
  • Use device PINs and recovery seed protections as primary safeguards — Bridge only facilitates communication, it does not replace device security.

How Bridge interacts with browsers

Browsers that support WebUSB or modern APIs may communicate directly with a Trezor device. In cases where direct communication is blocked (older browsers, OS limitations), Trezor Bridge acts as a fallback that handles USB interactions and exposes a local HTTP or WebSocket API the browser can securely call. Browser-level prompts and user permissions remain essential — the browser or wallet UI must request access and the device must be confirmed physically.

Advanced configuration & CLI

Advanced users can configure Bridge behavior, logging, and debug settings through a configuration file or command-line flags (when supported). This is useful for diagnosing connection issues or integrating with custom software. However, change settings only if you understand the implications.

Troubleshooting common issues

Connectivity issues are the most common support request. Below are practical fixes:

Bridge not detected by the app

  1. Confirm the Bridge service is running (use OS services list or system monitor).
  2. Restart the Bridge service and the host application.
  3. Try a different USB cable or port (prefer direct ports over hubs).
  4. Reinstall Bridge and reboot the system.

Device not recognized after macOS update

macOS updates sometimes change USB permissions or driver behavior. Reinstall the latest Bridge package and ensure system permissions allow the Bridge process to access USB devices. On Apple Silicon Macs, ensure you selected the proper installer architecture.

Firewall or antivirus interfering

Temporarily disable or add an exception for Bridge in your firewall/antivirus, ensuring only local loopback communication is allowed. Restore protections after confirming functionality.

Multiple conflicting wallet applications

Close other wallet apps that might open exclusive USB connections. Only one application should actively hold the device connection at a time.

Logs & support

Gather logs from the Bridge (if logging is enabled) and from the host application. These help support diagnose issues quickly. Do not share your recovery seed or private keys when asking for help.

Best practices & operational tips

To maximize reliability and security with Trezor Bridge:

  • Use official wallets and apps that explicitly support Trezor Bridge.
  • When possible, prefer direct WebUSB connections for simplicity; use Bridge as a robust fallback.
  • Maintain a small inventory of quality USB cables and prefer direct motherboard ports to USB hubs for consistent behavior.
  • Log connection attempts and errors when integrating Bridge in larger systems to speed debugging.

Backup and recovery planning

Remember: Bridge is an integration layer — your recovery seed and device PIN remain the ultimate access control. Keep multiple safe backups of your seed, consider metal backups, and plan for device loss or failure by testing recovery procedures on a secondary device (with a small, safe amount first) so you're familiar with the process under stress.

Frequently Asked Questions

1. Do I always need Trezor Bridge to use my Trezor?

Not always. Some modern browsers and apps can use WebUSB to talk directly to your Trezor. However, Trezor Bridge is recommended for maximum compatibility across operating systems and older browsers. Bridge provides a stable fallback when direct communication is not available.

2. Is Trezor Bridge safe to install?

Yes, when obtained from official channels. Official Bridge releases are signed and intended to run only on your local machine, listening to local-only ports. Always verify the download source and checksum to ensure integrity.

3. Will Bridge expose my Trezor to the internet?

No. By default Bridge binds to the loopback interface (localhost) which is accessible only from the local computer. Do not change Bridge network bindings to expose the service to remote networks.

4. How do I uninstall Trezor Bridge?

Use your operating system's normal uninstall mechanism (Add/Remove Programs on Windows, drag-to-trash or package uninstaller on macOS, package manager on Linux). Reboot after uninstalling to remove lingering services.

5. My browser still can't find the device even after installing Bridge — what now?

Try restarting the browser and Bridge service. Confirm Bridge is running and that firewall/antivirus isn't blocking local ports. Try a different browser or reinstall the browser extension if applicable. If problems persist, collect logs and contact official support.

Developer notes & integration

For developers building integrations that interact with Trezor Bridge, follow the official API documentation and use authenticated, ephemeral sessions. Respect user consent flows and ensure that all operations requiring user approval are confirmed on the physical device. Avoid storing sensitive secrets on the host machine, and keep communications limited to the local interface.

// Example pseudocode to detect Bridge
fetch('http://127.0.0.1:21325/info')
  .then(r => r.json())
  .then(info => console.log('Bridge status', info))
  .catch(err => console.error('Bridge not running', err));

Always consult the official developer docs for precise endpoints and secure handling of device requests.