Trezor Bridge — Secure Gateway to Your Hardware Wallet

What is Trezor Bridge?

Trezor Bridge is a lightweight, cross‑platform background service that enables secure and consistent communication between your Trezor hardware wallet and applications such as Trezor Suite or browser-based wallets. Because modern browsers restrict direct access to USB devices for security reasons, Bridge acts as a local intermediary: it listens on your computer (usually on a localhost port), accepts commands from trusted client software, communicates with the Trezor device over USB, and returns responses — all while never exposing your private keys or seed phrase. :contentReference[oaicite:0]{index=0}

In older releases, Trezor used browser plugins (e.g., Chrome Connector) to connect. But Bridge replaces those legacy methods, offering more robust and compatible transport across operating systems and browser environments. :contentReference[oaicite:1]{index=1}

Key Features & Benefits

Local‑Only Communication

Bridge listens on `localhost` (127.0.0.1) only — it does not expose APIs to external networks or over the internet. All message traffic stays internal to your machine. :contentReference[oaicite:2]{index=2}

Cross‑Platform Support

Available for Windows, macOS, and Linux. Bridge abstracts away OS-specific USB quirks so that client software can use the same interface across platforms. :contentReference[oaicite:3]{index=3}

Secure by Design

Bridge never handles signing or key storage. All sensitive operations happen on your Trezor device itself. Bridge is only forwarding validated requests. :contentReference[oaicite:4]{index=4}

Improved Compatibility

Works with multiple browsers (Chrome, Firefox, Edge, Brave) and avoids compatibility issues introduced by browser updates or removed plugin support. :contentReference[oaicite:5]{index=5}

Automatic Updates & Versioning

Bridge can detect when a new version is available and prompt you to update. This helps keep security and compatibility intact. :contentReference[oaicite:6]{index=6}

Low Overhead & Lightweight

The service is built to run quietly in the background with minimal CPU or memory footprint, only activating USB channels when needed. :contentReference[oaicite:7]{index=7}

Installation & Setup

Follow these recommended steps to install and configure Trezor Bridge on your computer:

Download from official source
Go to the official Trezor site (for example, `trezor.io/bridge`) and select the installer appropriate for your operating system. Always verify the URL and avoid third‑party downloads. :contentReference[oaicite:8]{index=8}
Run the installer
- **Windows**: run `.exe` or `.msi`, accept administrator permissions. - **macOS**: open `.dmg`, drag to Applications, allow USB permissions. - **Linux**: use `.deb`, `.rpm` or other package mechanisms (e.g. `apt install`), or run the binary manually. :contentReference[oaicite:9]{index=9}
Allow permissions / system prompts
On macOS or Linux, you might need to allow Bridge in security settings or grant access to USB devices. On Windows, ensure drivers are accepted. :contentReference[oaicite:10]{index=10}
Restart or reload browser / app
After installation, close and reopen your browser or Trezor Suite so it can detect Bridge. :contentReference[oaicite:11]{index=11}
Connect your Trezor device
Plug your Trezor via USB. The client application (Suite or web app) should detect Bridge automatically and prompt for unlocking or recognizing the device. :contentReference[oaicite:12]{index=12}
Approve connection on device
When prompted, verify that the app domain and handshake details match what you expect, then approve on the device. This ensures the connection is legitimate. :contentReference[oaicite:13]{index=13}

Security & Privacy Model

Trezor Bridge is built with several layers of protection to ensure that your private keys and seed never leave your hardware wallet. Below are the core security principles and recommendations:

Private keys never exposed: Bridge does not and cannot sign transactions or manage keys — all of that happens on your device itself. :contentReference[oaicite:14]{index=14}
Origin verification: Bridge validates the origin (which client app is making requests) and only allows known, trusted clients to connect. :contentReference[oaicite:15]{index=15}
Local-only interface: Bridge binds to `localhost` and does not open network interfaces accessible to external systems. :contentReference[oaicite:16]{index=16}
Signed updates: Bridge installers and updates are cryptographically signed; always verify checksums or signatures before installing. :contentReference[oaicite:17]{index=17}
Minimal privileges: Bridge requests only the OS permissions it needs (USB access, local loopback). It does not require broader system privileges. :contentReference[oaicite:18]{index=18}

Important: Bridge helps secure the connectivity layer, but it cannot protect you against malware or phishing attacks. Always use a clean, trusted computer, verify transaction details on the Trezor device screen, and never enter your seed or passphrase into any software. :contentReference[oaicite:19]{index=19}

Troubleshooting Common Issues

“Bridge not detected / not running”

This is the most frequent error reported by users. Possible causes:

Bridge service failed to start — try rebooting your computer.
A firewall or security software blocked Bridge’s local port.
Old or conflicting Bridge installations — uninstall previous versions and reinstall. :contentReference[oaicite:20]{index=20}
Browser didn’t reload — close and reopen it so it picks up Bridge. :contentReference[oaicite:21]{index=21}

USB connection or cable issues

Sometimes the issue is physical: try a different cable, another USB port (avoid hubs), or check for loose connectors. Also, ensure the OS has permitted USB device access. :contentReference[oaicite:22]{index=22}

Permission or driver errors (macOS / Linux)

On macOS, you might need to allow Bridge in “Security & Privacy” settings. On Linux, ensure udev rules or user permissions allow USB device access. :contentReference[oaicite:23]{index=23}

Version mismatch or outdated Bridge

If your client software expects a newer Bridge version, updating Bridge may resolve issues. Also ensure Trezor Suite or your browser interface is up to date. :contentReference[oaicite:24]{index=24}

Conflicts or multiple installations

If multiple Bridge versions or alternative USB mediation tools exist, they may conflict. Uninstall all except the official version. :contentReference[oaicite:25]{index=25}

Frequently Asked Questions

Do I always need Bridge to use Trezor?

In many desktop or web contexts, Bridge is recommended to ensure compatibility and stable connection. Some browsers (e.g. Chrome) support WebUSB, which might allow direct connection without Bridge, but Bridge improves reliability. :contentReference[oaicite:26]{index=26}

Is Bridge open source?

Yes — Bridge components are maintained in public repositories and are auditable. :contentReference[oaicite:27]{index=27}

Can Bridge access my private keys or seed?

No. Bridge acts only as a communication relay. All signing and private key operations are done on the Trezor device itself. :contentReference[oaicite:28]{index=28}

How do I verify the Bridge installer?

Use checksums or digital signatures published alongside the download. Compare hashes or signatures before installing to prevent tampered downloads. :contentReference[oaicite:29]{index=29}

What happens if I uninstall Bridge?

Without Bridge (or a supported transport), many browser‑based wallet tools may not detect or communicate with the Trezor device. You may lose functionality until you reinstall or use a native transport. :contentReference[oaicite:30]{index=30}