What is Trezor Bridge?
Trezor Bridge is a small, platform-specific application that lets web pages talk to a Trezor hardware wallet over USB. Browser security prevents web pages from directly accessing USB devices in a convenient way across every OS, so the Bridge acts as a local intermediary. When a compatible wallet interface needs to request a signature or show an address, the web page communicates with the Bridge, which then forwards the request to the connected Trezor device. This design isolates cryptographic key operations on the hardware device while enabling smooth browser experiences.
Why use it?
The Bridge is useful when you want an easy, browser-based interaction with your hardware wallet without manually installing device drivers or working at the command line. It provides a stable, cross-platform channel for popular wallet interfaces, letting them call into the physical device for approvals, PIN entry, and signing. Because private keys never leave the device, the Bridge itself handles only USB-level communications and not cryptographic secrets.
Installation & updates (high level)
Typical installation is straightforward: download the official Bridge package from Trezor's website for your platform and run the installer. The Bridge runs in the background and listens on a localhost port for browser requests. When updates are released, it’s best practice to apply official updates from trusted sources to fix bugs and improve compatibility. If you use a firewall or strict security rules, allow the Bridge's localhost traffic so your wallet interface can find it.
Security considerations
The strongest protections come from the Trezor hardware itself: your seed and private keys are stored on the device and protected by your passphrase and PIN. Treat the Bridge like any utility — keep it updated from the official site, avoid installing modified copies from untrusted sources, and only connect your Trezor when you intend to sign transactions. If a website prompts an unexpected request, decline it on the device and review what the originating site is asking for.
Troubleshooting tips
If a browser cannot detect your Trezor, check that the Bridge is running, that the cable is fully seated, and that the device screen shows its idle state. Try a different USB port or cable (data-capable cable required). Restarting the Bridge process or the computer can clear stale connections. Avoid interactions with unknown or suspicious web pages while connecting your wallet.
Developer & privacy note
For developers, the Bridge exposes a local HTTP API constrained to localhost and typically uses a short-lived token for pairing. From a privacy standpoint, the Bridge does not transmit transaction details off your machine except to the web page you explicitly visited. Be mindful of the websites you use with any hardware wallet — always confirm addresses on the device before signing.