Trezor Bridge — The Secure Gateway to Your Hardware Wallet^®

Introduction

Trezor Bridge is the bridge — literally — between your Trezor hardware wallet and the software that manages it. For many years, Bridge allowed browsers and desktop apps to communicate with Trezor devices reliably and securely. While the Trezor ecosystem has evolved (with Trezor Suite and web-based integrations), understanding Bridge — its role, how it works, and how to manage it — remains essential for users who interact with legacy flows or specific third-party integrations.

What is Trezor Bridge?

At its core, Trezor Bridge is a lightweight local service (a small daemon) that speaks USB and exposes a secure HTTP API to client applications. It translates messages between the browser or desktop software and the hardware device, handling USB permissions, sessioning, and message framing while keeping the sensitive cryptographic operations on the device itself.

Why it existed

Historically, browsers exposed limited and inconsistent access to USB devices. Bridge provided a consistent, cross-platform way for web apps and desktop apps to find and talk to Trezor devices without compromising security. It minimized the amount of platform-specific code that wallet developers needed to write and provided a single hardened gateway for communication.

Key responsibilities

• Expose a local API for applications (session and device discovery)
• Manage USB permission flows and device enumeration
• Serve as a security boundary — device keys never leave the hardware
• Provide cross-platform installers for Windows, macOS, and Linux

Current status & migration

Important: Trezor has been modernizing its stack. The official guidance now recommends using Trezor Suite (desktop or web) and modern browser APIs such as WebUSB where supported. As part of these changes, the standalone Trezor Bridge utility has been deprecated and users are advised to transition to Trezor Suite or WebUSB-based flows when possible.

What this means for users

If you currently have Trezor Bridge installed and you use Trezor Suite or the Trezor web app, check the official guidance: in many cases Trezor Suite replaces the need for the standalone Bridge, and WebUSB provides direct browser access. If a third-party site still prompts for Bridge, ensure you download installers only from official sources and follow support guidance when troubleshooting.

Security note

Never download Bridge or any Trezor-related binary from unofficial domains. Official installers and documentation appear on trezor.io and the official support pages. Removing outdated or orphaned Bridge installations may be recommended if you are migrating to Trezor Suite.

How Bridge works (brief technical)

Bridge runs locally and listens on a loopback HTTP port. Client apps open sessions and exchange protocol buffer (protobuf) messages which the Bridge forwards to the Trezor device over USB HID. The Trezor device then performs sensitive operations (key derivation, signing, seed generation) on-device and returns structured responses. The client never sees private keys.

Compatibility

Legacy Bridge versions were compatible with modern Chrome and Firefox releases of their time. For specific OS packages, community repositories (like certain Homebrew taps) and official installers were provided to make installation simple. Note that distributions without systemd may have had compatibility issues on Linux for older packages.

Troubleshooting common issues

Device not detected

If Trezor Suite or a web app doesn't see your device: check USB cables, try different ports, ensure the device is unlocked (if required), and follow the official troubleshooting guide. If Bridge was involved, uninstalling and reinstalling Bridge or switching to Trezor Suite can resolve interoperability problems.

Permission problems (browsers)

Modern browsers provide device permission prompts. If a site still expects Bridge, you may see different behavior; follow the specific integration guidance and avoid granting permissions to unknown pages. Prefer official endpoints such as the Trezor web app or Suite.

Best practice

Keep your device firmware up to date. Use official packages, and — when in doubt — consult the support center for step-by-step instructions rather than third-party tutorials that link to external downloads.

Recommendations

• Transition to Trezor Suite desktop or web when possible.
• Uninstall deprecated Bridge versions if advised by official guidance.
• Download only from trezor.io and verify signatures where provided.
• Follow official troubleshooting guides before reaching out to support.