What is Trezor Bridge?
Trezor® Bridge® is a lightweight local connector that establishes a secure, private channel between your web browser and your Trezor hardware device. It acts as a translator and gatekeeper: the browser cannot speak to the device directly, so Bridge handles the handshake and mediates requests while preserving the device’s fundamental promise — private keys never leave the hardware.
Bridge is intentionally limited in scope: it does not hold secrets, it does not upload recovery material, and it does not itself verify funds. Its job is one simple, auditable job — facilitate secure communication. That restraint reduces the attack surface and makes system reasoning much easier for savvy users and auditors alike.
At its heart, Bridge opens a small local port and registers an internal protocol that the browser can call. When a user navigates to an official web wallet or the official Suite and attempts to connect their hardware device, the page issues a request to Bridge. Bridge validates the request origin, forwards the message to the device via USB, and then returns a signed response or status update — all while preventing any raw seed, PIN, or private material from being exposed to the page.
Install Bridge; it runs in the background and is only accessible from the local machine. The installer places a trusted binary and a small service to manage connectivity.
When your browser wants to talk to your Trezor, it calls the Bridge endpoint. Bridge checks that the caller is allowed and that the device is present.
Bridge forwards signed transaction requests to the device; the device displays human-readable transaction details for you to verify and confirm using physical buttons.
This architecture prioritizes human verification. No amount of remote malware can approve a transaction unless a real person verifies details on the hardware device’s screen. Bridge is the courier; your device is the judge.
Security is layered. Bridge itself holds almost no sensitive material — its principal responsibilities are authentication, logging, and acting as a transport. The high-level security posture includes several elements:
The following recommendations are practical actions you can take to maximize security while using Bridge with your Trezor hardware wallet:
Adopt a routine where large transfers require additional procedural checks — e.g., validate on a second device or delay authorization to reduce impulsive mistakes.
No. Bridge is a transport service. Recovery phrases, PINs, and private keys remain on the Trezor hardware and are never transmitted to Bridge or the browser.
No. Bridge accepts only local requests and cannot remotely sign transactions — signature approval must be done physically on the device. However, keep your host machine clean and avoid untrusted websites.
Download updates from official channels and verify checksums/signatures if available. After installing, confirm Bridge’s behavior with a small test transaction before large moves.
Often, yes. For browser-based wallets and certain web-based versions of the official Suite, Bridge ensures a reliable connection across platforms. Native desktop Suite builds may not require Bridge.
Consult official documentation, follow release notes for Bridge and device firmware, and engage with community audits and security write-ups for more technical detail.