What is Trezor Bridge?
Trezor Bridge is a lightweight desktop service (a small background application) created by SatoshiLabs to enable secure communication between your Trezor hardware wallet and modern web browsers or desktop applications. Unlike older browser plugins, Bridge runs locally on your computer and acts as a secure messenger: it receives requests from an application or website, relays them to your physical Trezor device over USB, and returns the signed response. This architecture isolates the wallet's secret keys on the hardware device while allowing user-friendly interaction with web-based wallets and dApps.
How it works — the basics
- When a supported website wants to interact with your wallet, it sends a request to the local Bridge service.
- Bridge forwards that request to the connected Trezor device over USB.
- The user confirms actions (like signing a transaction) directly on the Trezor device screen, ensuring the private key never leaves the device.
- Bridge returns the signed result to the website or app.
Installation & basic setup
Installing Bridge is straightforward: download the official installer from Trezor's website and run it. Bridge supports Windows, macOS, and Linux. During installation you may see a system prompt asking to allow a local service to run — this is Bridge starting a local server (usually on http://127.0.0.1 or a similar loopback address). After installation, connect your Trezor via USB and open the web app you want (for example, Trezor Suite or a compatible wallet). The website will detect Bridge and prompt to connect to the device.
Important practical tips: always download Bridge from the official source, keep your OS and browser up to date, and restart your computer after first installing Bridge if connection problems appear.
Security considerations
Bridge itself is a utility that runs locally and does not have access to your seed phrase or private keys — those remain on the hardware wallet. However, security depends on several parts working correctly:
- Official software: Only install Bridge from the official Trezor domain or verified distribution channels.
- Local machine integrity: If your computer is compromised by malware, attackers might attempt to manipulate the website or the requests sent to Bridge. The Trezor device mitigates this by requiring on-device confirmation and showing transaction details for verification.
- Browser hygiene: Use a modern browser, avoid suspicious extensions, and confirm that the site you're interacting with is legitimate (check domain & certificate).
Troubleshooting common issues
If Bridge doesn't detect your device, try these steps in order:
- Reconnect the USB cable and try a different USB port. Prefer direct motherboard ports over hubs.
- Ensure your Trezor is powered on and unlocked (if required by the device model).
- Restart Bridge (on Windows this can be done via the system tray icon; on macOS or Linux, quit and restart the service or run the installer again).
- Temporarily disable browser extensions that may intercept USB or local host traffic.
- Check OS-level permissions — some systems require explicit permission for apps to access USB devices.
If problems persist, consult official logs or the Trezor support documentation for platform-specific instructions.
Compatibility & alternatives
Trezor Bridge is designed to work with Trezor devices and web applications that support the Trezor Connect API. Some desktop apps communicate with Trezor via alternate methods (like native integrations) and may not require Bridge, but many web-based wallets still rely on Bridge for a reliable USB bridge between browser and device.
Practical best practices
- Keep Bridge and your Trezor firmware updated. Firmware updates fix bugs and improve security.
- Use a dedicated device for significant holdings and consider a passphrase for additional security layers.
- Verify addresses and transaction details on the Trezor's screen before approving.
- Keep recovery seeds offline and never enter them into a computer or phone.
When to update or reinstall Bridge
Check for updates if a website or app warns of incompatibility, if your Trezor firmware has been updated, or if you observe intermittent connectivity problems. Reinstalling Bridge can often resolve stale configuration or permission issues. Only use the official installer from the Trezor website to avoid counterfeit installers.
Summary — why Bridge matters
Trezor Bridge plays a small but critical role in the user experience of hardware wallets: it allows modern browsers and web wallets to interact securely with hardware devices while keeping sensitive keys offline. Proper installation, keeping software up to date, and following best security hygiene will let you benefit from convenient web interaction without sacrificing the hardware wallet’s security guarantees.