1. What is Trezor Bridge?

Trezor Bridge is a small local service developed by SatoshiLabs that creates a secure communication layer between your computer’s web browser and a Trezor hardware wallet (Model One or Model T). As browsers have tightened access to USB and HID interfaces for security reasons, Bridge provides a reliable, system-level path for web applications to talk to your device without exposing sensitive information to the web.

It effectively replaces legacy browser extensions and acts as an automatic background helper that handles USB communication, device detection, and request routing for supported wallet software and websites.

2. Why Trezor Bridge exists

The web platform has evolved: older browser APIs were deprecated and some functionality that extensions once provided no longer works consistently across browsers. Trezor Bridge exists to solve several practical problems:

• Compatibility: Runs independently of changing browser APIs and avoids sudden breakage when browsers update.
• Security: Limits the attack surface by keeping sensitive operations on-device and handling communication through localhost only.
• Stability: Reliable device detection and fewer false negatives compared to browser-only solutions.
• Future-proofing: Provides a fallback when WebUSB or other direct browser access is unavailable or blocked.

3. How Trezor Bridge works

Although Trezor Bridge runs largely out of sight, the basic flow of communication is straightforward:

1. You plug your Trezor into your computer via USB.
2. You open a Trezor-enabled website or the Trezor Suite web app.
3. The website sends a request to the local Bridge service running on your machine.
4. Bridge passes the request to the Trezor device; the device displays a prompt and waits for your confirmation.
5. After you confirm an action on the device, the result is sent back through Bridge to the website.

At no point does the Bridge transmit private keys, the recovery seed, the PIN, or passphrases. All cryptographic signing and key handling happen inside the device itself. Bridge simply transmits requests and device responses over a local channel.

Bridge complements WebUSB: when WebUSB is available, some web interfaces will attempt to use it directly; Bridge serves as a robust fallback for browsers or environments where WebUSB is unavailable or unreliable.

4. How to install Trezor Bridge

Installation is intentionally simple — Bridge runs as a background service and usually requires minimal user interaction. The steps vary by operating system.

Windows

Download the official installer from the Trezor website, run the executable, and follow the prompts. Once installed, Bridge starts automatically and will detect your device when plugged in. Restart your browser after installation to ensure detection.

macOS

Download the macOS package, move the app into /Applications, and open it. macOS may prompt you to grant permissions under System Preferences → Security & Privacy. If the browser doesn’t see your device, restarting the browser often resolves the issue.

Linux

Linux distributions typically provide DEB or RPM packages, or a tarball. Install via your package manager and make sure udev rules are added so non-root users can access USB devices. After installation, restart your browser or log out and back in if necessary.

Note: For many users, the Trezor Suite desktop app removes the need for Bridge, because the desktop app communicates directly with the device.

5. Common issues & troubleshooting

Browser can’t detect the device

Common causes include an outdated Bridge, WebUSB interference, blocked USB permissions, or a faulty cable. Useful steps:

• Update to the latest Trezor Bridge release.
• Restart your browser.
• Try a different USB cable or port.
• Temporarily disable extensions that might interfere with USB communication.

Device detected but actions fail

This can happen when firmware or software is outdated or when another app is locking access to the device. Fixes:

• Update your Trezor firmware via Trezor Suite.
• Close other apps that may access Trezor and try again.
• Restart the computer if the problem persists.

Bridge not running

On Windows and macOS it should start automatically. Check the system tray or menu bar. If it’s not running, reinstall Bridge and verify startup settings. On Linux, verify udev rules and service status.

6. Security considerations

Trezor’s security model relies on the hardware wallet performing sensitive operations locally; Bridge does not change that model. Key security highlights:

• No private data exposure: Bridge never receives seeds, private keys, PINs, or passphrases.
• Localhost-only: The Bridge service listens only on your machine and isn’t accessible remotely.
• Open source: The Bridge code is public and can be audited by third parties.
• Physical confirmation required: Transactions and other critical actions require manual confirmation on the device.

7. Alternatives

There are a few scenarios where you may use an alternative to Bridge:

• WebUSB: When supported, a browser can communicate directly with a Trezor device via WebUSB. This is convenient but can be less reliable across environments.
• Trezor Suite Desktop: A native desktop app that communicates directly with your device without Bridge.

Even when alternatives exist, Bridge remains the most consistent option for browser-based workflows.

8. Best practices for using Trezor Bridge

Follow these simple habits to keep your Trezor experience smooth and secure:

• Always download Bridge from the official Trezor website.
• Keep Trezor firmware, Suite, and Bridge up to date.
• Use a good-quality USB cable and avoid hubs that can cause communication problems.
• Close browser tabs and apps that might attempt to access the device at the same time.
• Always confirm the details on the device display before approving any transaction.

Conclusion

Trezor Bridge® is a small but essential component for many users who rely on web-based wallets and decentralized applications. By acting as a secure, local communication layer it bridges the gap between modern browsers and hardware wallets — providing better compatibility, stability, and a reduced chance of breakage when browser APIs change.

Whether you use Trezor Suite Web, third-party browser wallets, or web-based dApps, installing and maintaining Trezor Bridge ensures a smoother, safer connection to your Trezor hardware wallet. If you prefer not to use Bridge, consider the Trezor Suite desktop application for native connectivity.

Need the installer? Visit the official Trezor website.