Trezor Bridge: Secure Connection for Your Hardware Wallet

What is Trezor Bridge?

Trezor Bridge is an official background service developed by SatoshiLabs that acts as a secure communication layer between your computer and a Trezor device. Because web browsers deliberately restrict direct hardware access for security reasons, Bridge provides a controlled local endpoint that the browser or desktop wallet can use to send commands to and receive responses from the Trezor device.

Unlike browser extensions or direct USB drivers, Bridge is designed specifically to minimize attack surface: it only exposes a local API and listens on loopback (your machine only), not on a network interface exposed to the internet. That design keeps interactions local and reduces the risk of remote interference while enabling modern web-based wallet interfaces to operate smoothly.

Why you need it

Many wallet front-ends and web apps rely on the WebUSB or WebHID APIs to talk to hardware wallets. Because of browser security and compatibility layers, those APIs don’t always provide a consistent cross-platform experience. Trezor Bridge fills the gap by translating the wallet application's requests into a protocol the device understands, providing:

• Reliable connectivity across Windows, macOS, and Linux
• Compatibility with both web-based and desktop wallet interfaces
• Simple installation without low-level USB drivers
• Local-only communication to keep traffic on your machine

How Trezor Bridge works

When installed, Bridge runs as a background process and listens to a local port on the loopback interface (for example 127.0.0.1). Wallet software connects to that local port through standard HTTP or WebSocket requests. Bridge then interacts with the USB-connected Trezor using a low-level protocol and relays JSON-formatted messages back and forth.

Crucially, Bridge itself does not store private keys or recovery seeds. All sensitive cryptographic operations happen inside the Trezor hardware wallet — Bridge only relays signed requests and responses. This separation preserves the hardware wallet’s role as the secure vault for your keys.

Installation & setup

Installing Bridge is straightforward. Download the official installer from the Trezor website and follow the platform-specific steps. Typical flow:

1. Visit the official Trezor website or open Trezor Suite.
2. Download the Bridge installer for your OS (Windows, macOS, Linux).
3. Run the installer and grant the necessary permissions.
4. Plug in your Trezor and open the wallet interface. The app should detect the device automatically.

Note: Always download Bridge from the official Trezor domain or the Trezor Suite to avoid tampered installers. If in doubt, verify checksums provided on the official site.

Security considerations

Trezor Bridge enhances usability without changing the security model of the Trezor device. That said, some practical precautions are important:

• Only use official releases: Download Bridge and Suite from SatoshiLabs’ official channels to avoid malicious binaries.
• Keep software updated: Bridge, Trezor firmware, and your wallet software receive security fixes periodically. Install updates promptly.
• Verify websites: Access wallet web apps through trusted URLs and check for HTTPS. Beware of phishing pages that mimic wallet UIs.
• Local access only: Bridge listens on loopback. If you see warnings about remote access or unusual ports, investigate and stop the service if necessary.
• Protect your machine: A compromised host could attempt to manipulate transaction requests shown in the wallet UI. Use anti-malware measures and consider a dedicated device for large holdings.

Troubleshooting common issues

Here are quick fixes for the most common connectivity problems:

• Device not detected: Reconnect the USB cable, try a different port, or restart Bridge. Ensure the cable supports data (some charge-only cables won’t work).
• Browser blocked connection: Grant the site permission to access the device, or use Trezor Suite if browser restrictions persist.
• Old Bridge version: Uninstall previous Bridge versions and install the latest release to resolve compatibility issues.
• Firewall or network tool interference: Since Bridge operates locally, firewall rules or privacy tools might block loopback traffic—check settings and allow local connections.

Best practices for safe use

To make your Trezor experience both convenient and secure, follow these best practices:

• Keep your recovery seed offline and written on paper (or a metal backup). Never enter it into a computer or phone unless explicitly required during device recovery.
• Check the transaction details on the Trezor device screen before confirming. The hardware display is the ultimate source of truth for what you sign.
• Use strong PINs and enable passphrase protection if you need an extra account-level password. Remember: passphrases add security but also add responsibility — losing them can mean permanent loss of funds.
• Regularly update firmware using official Trezor tools and follow the staged update instructions shown by the device.