Trezör® Bridge® — Connect Your Web3 World Securely™

Trezör Bridge is the lightweight local bridge that connects your Trezor hardware wallet to web3 apps and browser-based wallets. This 2500-word guide explains what Bridge does, how to install and use it safely, developer notes, security best practices, troubleshooting, and frequently asked questions.

What is Trezör® Bridge®?

Trezör Bridge is a small background application that runs on your computer and acts as a secure communication layer between web-based applications (dApps, web wallets, and the Trezor Suite web interface) and your Trezor hardware device. It exposes a local API that sites can use to communicate with the device over USB without requiring browser extensions or unsafe direct USB access. Bridge ensures that only authorized webpages can request operations from your Trezor, and it forwards user approvals to the device for secure signing.

Key idea: Bridge does not hold your keys or seed. It is simply a facilitator that passes messages between the browser and your Trezor device while enforcing permission boundaries and allowing the device itself to perform all cryptographic operations.

Why use Trezör Bridge?

  • Compatibility: Enables web-based wallets and dApps to interact with Trezor devices in modern browsers.
  • Security: Keeps private keys isolated on the hardware; Bridge only passes user-approved commands.
  • User experience: Removes the need for browser extensions and simplifies the connection flow for users and developers.
  • Cross-platform: Available for Windows, macOS, and Linux.

Download and verify Trezör Bridge

  1. Open a browser and go to the official Trezor downloads page at trezor.io/start or the Trezor Bridge specific page.
  2. Select the Bridge installer for your operating system (Windows, macOS, Linux) and download the package.
  3. When available, verify the download's checksum or signature against the value published on the official page to ensure integrity.
  4. Run the installer and follow on-screen prompts. You may need to authorize the installation with administrator privileges.

Only download Bridge from the official Trezor domain. Phishing sites may attempt to present modified installers that can compromise security.

Install & run Bridge

Installation is straightforward. Bridge runs as a background service (daemon) and listens on a local port for requests from the browser. Browser-based Trezor integrations detect and use Bridge automatically when the service is running.

  1. Run the downloaded installer and follow OS-specific prompts. On Windows, the installer will register Bridge as a service. On macOS and Linux, follow the package instructions for your distribution.
  2. After installation, Bridge should start automatically. If not, open the Bridge application from your system tray or start menu.
  3. Open your browser and navigate to a supported web wallet or Trezor Suite web. The site should detect Bridge and prompt you to connect your device when needed.

Using Bridge with web3 apps

Once Bridge is running, connecting to web3 apps follows a simple flow:

  1. Open a supported web wallet or dApp and choose the option to connect a hardware wallet or Trezor.
  2. The site will request a connection — Bridge relays this to your browser.
  3. When prompted, connect your Trezor device via USB and unlock it by entering your PIN on the device. The device may ask you to open a specific app (e.g., Ethereum).
  4. Approve the connection on the device if required. Now the dApp can request operations like reading addresses or requesting transaction signatures. For every signing operation, you will always confirm the details on-device before a signature is produced.

Bridge allows for address discovery and non-sensitive queries without exposing private keys. Any operation that needs key material will show a confirmation prompt on the Trezor device itself.

Security model and best practices

Bridge is designed with a minimal, security-first model:

  • Least privilege: Bridge only listens on localhost and accepts requests from browser tabs; it does not expose the device to the wider network.
  • User confirmation: Any operation that creates signatures or accesses sensitive data requires explicit approval on the Trezor device.
  • Origin checks: Modern integrations validate the requesting origin to prevent unauthorized cross-site requests.
  • Updates: Keep Bridge and your Trezor firmware up to date to benefit from security patches and protocol improvements.

Always verify the URL of the website before connecting your Trezor. Attackers can create convincing phishing sites that mimic legitimate dApps — check the domain carefully and prefer bookmarks for frequently used services.

Permissions & privacy

Bridge itself does not request personal data. It facilitates local USB communication between your browser and device. When connecting to web apps, be mindful of the permissions you grant: some dApps may request access to view addresses or request signatures for messages or transactions. Always read prompts and review transaction data on the device screen before approving.

Developer notes

Developers integrating Trezor support via Bridge should follow recommended patterns:

  • Use the official Trezor Connect library where possible — it provides a stable, audited interface for interacting with devices via Bridge.
  • Respect origin-based checks and use the library's popup or iframe modes to handle user flows.
  • Never request unnecessary permissions: only ask for addresses or signing operations when needed and provide clear UX explaining why the permission is required.
  • Test across platforms — Bridge behavior and USB permissions can differ between browsers and operating systems.

Refer to the Trezor developer documentation for API details, code samples, and best practices. Keep libraries up to date to incorporate security fixes.

Troubleshooting common Bridge issues

Bridge not detected by the browser

  • Ensure Bridge is running (look for the Bridge icon in the system tray or menu bar).
  • Restart the browser and Bridge service. Some browsers cache device states — restarting often resolves detection issues.
  • Check for firewall or security software that may block localhost ports used by Bridge.
  • Reinstall Bridge from the official site if detection problems persist.

Site cannot communicate with my device

  • Ensure your Trezor device is connected and unlocked (enter PIN on-device).
  • Open the specific cryptocurrency app on the device if the dApp requires a chain-specific app (e.g., the Ethereum app).
  • Confirm device prompts — without on-device approval signatures cannot be produced.

Permission errors or origin mismatches

Web apps must present correct origins and use the official libraries for origin checks. If you encounter origin mismatch warnings, ensure you are on the correct domain and that the web app integration is using the proper connection flow.

Keeping Bridge and firmware updated

Bridge and device firmware updates include security fixes and protocol improvements. Follow these steps to stay current:

  1. Install Bridge updates when prompted by the Bridge app or during a check on the official site.
  2. Open Trezor Suite or use the official update channels to apply firmware updates to your device. Firmware updates require on-device confirmation.
  3. For development, ensure your integration is compatible with the latest Bridge and library versions.

Do not install Bridge or firmware updates from untrusted sources. Always verify updates via official channels.

Frequently asked questions

Does Bridge store my private keys or recovery seed?

No. Bridge never has access to private keys or the recovery seed. It only forwards requests between the browser and the device. All sensitive operations require explicit approval on the Trezor device.

Can I use Trezor without Bridge?

You can use Trezor Suite desktop or other supported native apps without Bridge. However, Bridge is required for many browser-based dApps and web wallets that rely on its local API for device communication.

Is Bridge open source?

Parts of the Trezor software ecosystem, including libraries and tools, are open source. Check Trezor's official repositories for Bridge and related components to review code and documentation.

Resources & links