What is Trezor Bridge?
Trezor Bridge is a lightweight application designed to run in the background of your computer. Its primary function is to facilitate communication between your Trezor hardware wallet and supported web browsers.
In the past, browsers allowed direct communication with USB devices via plugins, but modern security standards have deprecated these methods. Trezor Bridge solves this by creating a local communication server (running on 127.0.0.1) that your browser can safely talk to. This ensures that when you visit a compatible wallet interface—like Trezor Suite for Web, MyEtherWallet, or MetaMask—the website can detect your device without compromising security.
Think of it as a specialized translator. Your browser speaks "web," and your hardware wallet speaks "USB protocol." Trezor Bridge sits in the middle, translating these messages instantly and securely, ensuring that your private keys never leave the physical device.
Background Service
Runs silently as a system service (trezord) without cluttering your desktop.
Enhanced Security
Verifies the authenticity of the calling website to prevent phishing attacks.
Faster Performance
Optimized data handling for quicker account loading and transaction signing.
Why You Need Trezor Bridge
While some modern browsers support the WebUSB standard, Trezor Bridge remains a critical component for a robust crypto management experience.
Universal Browser Support
Not all browsers support WebUSB (e.g., Firefox). Trezor Bridge ensures you can access your wallet on your preferred browser without restrictions. It provides a standardized connection method across Chrome, Firefox, Brave, and more.
Isolated Environment
By handling USB communication outside the browser context, Trezor Bridge adds a layer of isolation. This reduces the attack surface compared to direct browser-to-USB communication, keeping your digital assets safer.
Stability & Reliability
WebUSB connections can sometimes be interrupted by browser updates or strict privacy settings. Trezor Bridge operates independently of the browser version, offering a more stable and persistent connection for long sessions.
How Trezor Bridge Works
From a technical perspective, Trezor Bridge is a daemon process named trezord. When installed, it listens on a specific local port (typically 21325).
When you visit a Trezor-compatible website, the site sends an HTTP request to https://127.0.0.1:21325/. Because this is a local address, the request stays entirely within your computer.
- Step 1: You connect your Trezor device via USB.
- Step 2: The Trezor Bridge detects the USB connection and identifies the device model.
- Step 3: The web wallet (e.g., Trezor Suite Web) sends a request to the Bridge asking for device status.
- Step 4: Bridge verifies the request origin against a whitelist to ensure it's a legitimate application.
- Step 5: Bridge relays the command to the device (e.g., "Get Public Key") and returns the result to the browser.
Crucially, private keys never leave the device. The Bridge only transports public data and signed transaction payloads, maintaining the "cold storage" security model.
$ ps aux | grep trezord root 1234 0.0 0.1 trezord-go > Status: Running > Port: 21325 > Device: Connected > Encryption: TLS 1.2+
Installation Guide
Getting started with Trezor Bridge is straightforward. Follow the steps for your operating system.
Windows
- Go to the official Trezor website.
- Download the
trezor-bridge-x.x.x-win32-install.exefile. - Run the installer. You may need to grant Administrator privileges.
- Follow the on-screen wizard.
- Once finished, the
trezordprocess will start automatically. - Restart your browser to ensure the new bridge is detected.
macOS
- Download the
trezor-bridge-x.x.x.pkgfrom the official site. - Double-click the downloaded file to open the installer.
- Follow the installation prompts.
- If prompted, allow the application in "System Preferences" > "Security & Privacy".
- Disconnect and reconnect your Trezor device.
Linux
- Download the appropriate package (
.debfor Debian/Ubuntu or.rpmfor Fedora/CentOS). - Install using your package manager (e.g.,
sudo dpkg -i trezor-bridge.deb). - Ensure udev rules are configured correctly for USB access.
- The service should start automatically. You can verify with
systemctl status trezord.
Troubleshooting Common Issues
Device Not Detected
If the Bridge is installed but your device isn't showing up, try using a different USB cable. Many cables are "charge-only" and do not transmit data. Also, try a different USB port directly on your computer, avoiding USB hubs.
Bridge Process Not Running
Open your computer's Task Manager (Windows) or Activity Monitor (Mac) and look for trezord. If it's not running, try reinstalling the Bridge or starting the service manually.
Browser Cache Issues
Sometimes browsers cache old connection states. Clear your browser's cache and cookies, or try accessing the wallet in Incognito/Private mode to rule out extension conflicts.