What is Trezor Bridge?
Trezor Bridge is a lightweight local service that creates a secure, cross-platform communication channel between web applications (including Trezor Suite or supported web wallets) and your Trezor hardware device. It runs as a small background application on your computer and exposes a local API endpoint that browsers can call to talk to your device without requiring browser extensions. In short, it is the official, curated bridge between the browser and the hardware — designed for usability and security.
Why Bridge exists
Browsers intentionally restrict direct USB and HID access for security and compatibility reasons. Trezor Bridge fills this gap by offering a trusted local endpoint that handles USB transport and presents a consistent API. This simplifies integration for web apps, avoids the need for platform-specific browser extensions, and lets developers rely on a stable interface to the device while preserving the safety guarantees of on-device confirmations and isolated private key storage.
Installing Trezor Bridge — step-by-step
- Download Bridge from the official source: trezor.io/bridge. Choose the installer for your operating system (Windows, macOS, Linux).
- Run the installer and follow the on-screen prompts. Administrative privileges may be required on some systems.
- After installation the Bridge runs in the background and listens on a local port. Open Trezor Suite or your chosen web app and the app will detect the service automatically.
- If the web app still cannot see your device, confirm the Bridge is running (check your system tray or background services) and try reconnecting the Trezor device or restarting the browser.
Security model & best practices
Trezor Bridge itself does not hold private keys or perform signing — those actions happen on the hardware device. However, Bridge is a privileged local service, so you should follow best practices:
- Only download Bridge from the official site. (trezor.io/bridge)
- Verify installer signatures where available to rule out tampering.
- Run Bridge on trusted machines. If a machine is compromised, an attacker could attempt to relay fraudulent requests to the device (which will still require physical confirmation on-screen).
- Keep Bridge updated — updates fix bugs and security issues. Use official update channels. (Downloads)
- Always confirm addresses and transaction details on the Trezor device’s screen before approving any operation. On-device verification prevents remote manipulation from draining funds.
How Bridge interacts with browsers
Instead of requiring a browser extension, Bridge exposes a local HTTP(s) endpoint that the web application can call. Modern web apps use standardized libraries that discover Bridge and route JSON-RPC requests to the hardware via the service. The browser communicates only with localhost; Bridge handles USB/HID interactions with the Trezor device. This architecture reduces friction for users and simplifies deployment for web developers.
Troubleshooting common issues
If you encounter problems, try the following in order:
- Confirm the Trezor device is connected firmly and powered via USB.
- Check that Trezor Bridge is running. Restart Bridge or reinstall if necessary.
- Try a different USB cable and port. Avoid USB hubs unless they explicitly support HID devices.
- Restart your browser and, if needed, reboot the system to clear stale device sessions.
- Ensure no other apps are blocking USB access. On Linux, confirm udev rules are installed (see official docs).
- For macOS users, grant permissions if the OS requests them for local services or driver-like behavior.
Developer integration & APIs
Developers building integrations can rely on Trezor Bridge as the transport layer for communicating with the device. Trezor provides open-source libraries and specifications that describe the JSON-RPC over Bridge and the message formats used for device operations. If you’re creating a web wallet or integrating hardware signing, follow these rules:
- Use official client libraries (e.g.
trezor-connect) to avoid low-level USB handling. - Keep the signing UX clear: always present users with readable addresses and transaction details before signing.
- Never request or store private keys — signing should happen on-device and only the signed transaction should be returned to the web app.
- Respect the user’s privacy — avoid leaking metadata and consider Tor or privacy-preserving network options for advanced apps.
Bridge updates & compatibility
Bridge is actively maintained to support new OS versions and browser changes. Periodically, updates are released to improve performance, security, and device compatibility. Because Bridge sits between the browser and the hardware, keeping it updated ensures the best interoperability with evolving web standards and Trezor firmware versions. Check the official downloads page for the latest releases. (trezor.io/downloads)
Alternatives and related tooling
If you prefer alternatives to Bridge in some contexts, consider:
- Trezor Suite (desktop), which includes bundled transport and may not require a separate Bridge installation depending on platform. (Start guide)
- Command-line tools and developer APIs for headless workflows (see the GitHub repos). (GitHub)
Privacy considerations
Bridge itself does not transmit wallet data to remote servers. It enables local transport between your browser and device. Nevertheless, your on-chain activity and any information you share with web services may create linkages. To protect privacy, avoid address reuse, keep separate accounts for different uses, and consider network privacy tools when appropriate.
Resources & official links
Below are reference links for installation, support, developer docs, and community resources. Use only official pages when downloading installers or following setup instructions.
Trezor Bridge — official page Trezor Start guide Support & troubleshooting Downloads & installers Trezor GitHub organization Firmware & verification Trezor Academy Bridge developer notes (community wiki) Community forum Privacy & Tor options
Conclusion
Trezor Bridge plays an important, security-conscious role as the local gateway that connects web applications to your hardware wallet. It balances usability and safety by keeping private keys on the device while providing a stable, cross-platform transport layer for browsers. Install Bridge from the official source, keep it updated, and always verify on-device prompts before signing. For developers, using the official libraries and recommended UX patterns ensures secure, user-friendly integrations.