Introduction
Trezor Bridge® acts as a secure, local communication layer between your Trezor hardware wallet and web-based cryptocurrency interfaces. Instead of allowing direct browser access to USB devices, modern browsers require a small, trusted intermediary — Trezor Bridge — which safely relays messages between websites (like accounts or dApps) and your physical Trezor device.
Why Trezor Bridge matters
Browser security has improved significantly over the past few years. To maintain user safety and a predictable API across platforms, web browsers intentionally restrict direct hardware access. Trezor Bridge provides predictable cross-browser behavior, ensuring that interactions such as key signing, address verification, and transaction confirmations happen securely and reliably, regardless of whether you're using Chrome, Edge, Firefox (with the right setup), or other supported browsers.
How it works (high level)
- Install Trezor Bridge on your computer. It runs locally as a small background service.
- When a web app wants to communicate with your Trezor, it queries the bridge through a secure local endpoint.
- The bridge forwards the request to your connected Trezor device via USB or WebUSB if the browser supports it.
- Your Trezor displays prompts and requires you to confirm every sensitive action on-device — that human-in-the-loop step is critical to security.
Security model and best practices
The key security principle for Trezor — and hardware wallets in general — is that the private keys never leave the device. Trezor Bridge does not store your seed or private keys. It acts strictly as a messenger. Still, follow these best practices:
- Always download Trezor Bridge from official sources. Avoid third-party installers.
- Keep the firmware of your Trezor up to date, and verify releases through Trezor’s official channels.
- Confirm every on-device prompt carefully — screen spoofing attacks are prevented because user confirmation happens physically on the device.
- Use a trusted browser and close background tabs that you do not recognize when connecting your wallet.
Installing Trezor Bridge
Installation is usually straightforward: download the installer for your operating system (Windows, macOS, Linux), run it, and allow the service to run in the background. Once installed, your browser should be able to detect Trezor devices through the bridge or through supported WebUSB interfaces.
Common connection issues
Browser prompts and permission issues
Some browsers require explicit permission to allow web pages to use native messaging or USB. Ensure you allow the site to access the bridge; when in doubt, close the browser, reconnect the device, and try again.
Drivers and OS-level blocks
On certain operating systems, USB permissions or drivers can block access. On Linux, you may need udev rules; on Windows, ensure you allow the installer to add necessary drivers. Trezor's official install pages detail platform-specific steps.
Developer notes (optional)
If you are a developer integrating Trezor support into your web app, treat the bridge endpoint as untrusted input: validate and sanitize requests and always request the minimal permission necessary for an operation. Require user confirmation on the device for signing transactions or revealing sensitive metadata.
Use cases — when you'll see the Bridge
Typical scenarios include: sending cryptocurrency from a web wallet interface, interfacing with hardware-supporting dApps, authorizing a multisig transaction, or importing an address to read-only apps for balance checking. In all cases, the bridge simplifies compatibility while preserving the security guarantees of the hardware device.
Accessibility and usability
The Trezor ecosystem aims to be accessible: prompts are short and clear, and confirmations happen on-device so users with screen readers or accessibility tools in the browser still get consistent, secure results. If accessibility improvements are needed, Trezor’s open-source community welcomes contributions and feedback.
FAQ — Frequently Asked Questions
What is Trezor Bridge and do I always need it?
Trezor Bridge is a local intermediary service that allows your browser to talk to a Trezor hardware wallet. Depending on your browser and platform, you might be able to use WebUSB directly in some configurations; however, Bridge ensures cross-browser support and is the recommended method for most users.
Is Trezor Bridge safe?
Yes — Bridge only facilitates local communication and does not store private keys. The security-critical confirmations always happen on the Trezor device itself. Only install Bridge from official sources.
Can I use Trezor Bridge on multiple browsers?
Yes. Once installed, Bridge acts for any browser that supports the local messaging or WebUSB approach used by Trezor-compatible web apps.
What if my browser doesn't detect the Trezor?
Try these steps: (1) verify Bridge is running; (2) unplug and replug your device; (3) ensure permissions are allowed in the browser; (4) restart the browser or computer; (5) consult platform-specific guides for driver or permission issues.
How do I update Trezor Bridge?
Download the latest installer from the official site and run it; it will upgrade the existing service. Follow on-screen instructions and verify the installer is legitimate.
Will Trezor Bridge reveal my seed or private keys?
No. Bridge does not have access to sensitive secrets. Private keys remain inside the device and cannot be extracted through Bridge.
Can I use Trezor Bridge on mobile?
Mobile support is evolving. Some mobile browsers with WebUSB or WebHID support may interface with hardware devices, but for most phones, USB OTG and mobile compatibility will vary. Check device-specific docs.
Does Bridge support HID (Human Interface Device)?
Bridge supports the communication pathways required by Trezor; details vary by OS and device. Developers should check the official developer docs for current supported transports.
What browser should I use?
Use a modern, up-to-date browser (Chrome, Edge, or Firefox variants). For highest compatibility, follow the official Trezor recommendations and support pages.
Where can I get help?
Use the official support channels, community forums, or documentation for troubleshooting. If you suspect compromise, disconnect the device and seek official guidance immediately.
Final thoughts
Trezor Bridge simplifies connections between web wallets and your hardware device while preserving the core security property: private keys never leave your Trezor. Treat Bridge as an essential tool for safe web-based crypto interactions. For most users, installing Bridge from the official site and keeping both firmware and software up to date is the simplest path to secure and reliable usage.