What is Trezor Bridge?
Trezor Bridge is a lightweight background application that provides a secure, cross-platform communication channel between the Trezor hardware wallet and browser-based or desktop applications. Instead of relying on browser extensions, Bridge runs on the host computer and handles USB / WebUSB signaling and secure messaging with the device.
(Download & install guidance is available on Trezor’s official start page.)
Why Bridge matters — quick overview
Separation of duties
Bridge isolates low-level USB handling from web applications. This separation reduces attack surface inside the browser while allowing web apps to request operations from the Trezor device via standard, well-defined RPCs.
User experience
For users the Bridge is almost invisible: it starts on demand, makes device discovery fast, and lets a browser prompt you for confirmations displayed on the hardware device itself — keeping private keys away from the host OS and browser.
How Bridge works (technical primer)
Architecture
At its core, Bridge runs a local server and exposes a small API that browser libraries (like trezor-connect or the Trezor Suite) call to issue device commands. The hardware wallet still authorizes all critical actions (signing, key export, PIN entry) on-device.
Typical flow
- User opens a dApp or Trezor Suite in the browser.
- Web app requests connection to Trezor via the local Bridge service.
- Bridge talks to the device over USB and relays secure messages to the web app.
- Trezor prompts the user on-device for final confirmation (PIN, passphrase, button press).
A simple example (connect request)
// pseudo-code: web app asks Bridge to enumerate devices
fetch('http://127.0.0.1:21324/enumerate')
.then(r => r.json())
.then(devices => console.log('connected devices', devices));
Installation, deprecation notes, and the Trezor Suite
Historically, Trezor offered Bridge as a standalone installer for Windows and macOS. In recent years Trezor has moved toward integrating most connectivity into the Trezor Suite application and web-first flows; the standalone Bridge can be deprecated in favor of the Suite in some setups. If you rely on a separate Bridge, consult Trezor’s official guidance before uninstalling or upgrading. :contentReference[oaicite:0]{index=0}
Where to download
The canonical download and start page is the official Trezor “start” / Suite pages — always use Trezor’s site to avoid fake installers. :contentReference[oaicite:1]{index=1}
Security posture
Why it’s safe
Bridge does not store private keys or seeds — every cryptographic operation requiring secret material happens on the Trezor device. Bridge simply relays requests and responses. Even if Bridge were compromised, the attacker would still need on-device approvals to move funds. This layered design is a key reason hardware wallets remain one of the safest ways to custody crypto.
Keep Bridge updated
As with any system-level helper, updates are important. Trezor publishes firmware and software changelogs; check them if you depend on Bridge to keep compatibility and security current. :contentReference[oaicite:2]{index=2}
Troubleshooting (common issues & fixes)
Device not detected
Make sure your Bridge (or Trezor Suite) is installed, the cable and USB port are working, and your browser allows the local host connection. On some operating systems you may need to uninstall the old standalone Bridge if a newer Suite-managed connector is used. :contentReference[oaicite:3]{index=3}
Conflicting apps
If another program is claiming the USB device, close that program. Rebooting or reinstalling the latest Trezor Suite/Bridge installers often resolves conflicts.
Best practices
- Always download Bridge or Suite from Trezor’s official site.
- Verify checksums or the official instructions when available.
- Keep your Trezor firmware and Bridge/Suite up to date for security patches.
- Use device-confirmed passphrases and never reveal your seed to a computer.
Where to go from here
If you’re setting up a Trezor for the first time, follow the official “get started” walkthrough and use the latest Trezor Suite for the smoothest experience. If you maintain an advanced workflow (custom dApps, headless servers), learn the exact Bridge or connect API your integrations require.
Official resources
The links below go to official Trezor resources — ten instances provided and styled using the site’s recommended link color.