How Bridge works (simple)
Trezor Bridge runs as a small background service on your computer. When a web page needs to communicate with your Trezor device (for example, the Suite or a compatible exchange website), the page sends requests to the local Bridge. Bridge forwards these requests to the device over USB (or WebUSB where available). Each transaction must be confirmed on your Trezor device — the private keys never leave the hardware.
Compatibility & matrix
| Platform | Supported browsers | Notes |
|---|---|---|
| Windows (7+) | Chrome, Edge, Firefox | Installer includes driver support |
| macOS (10.12+) | Safari, Chrome, Firefox | Grant permissions on first run |
| Linux | Chrome, Firefox | Deb/RPM available; manual udev rules |
Security note
Bridge only listens on localhost and uses native OS APIs to communicate with USB devices. Always download Bridge from the official Trezor website and verify signatures where provided. If you are using shared or public machines, avoid installing Bridge there — your private key confirmations must remain under your control.
Below is a minimal example showing how an application might probe the local Bridge endpoint to check availability (for illustration only):
fetch('http://127.0.0.1:21325/version')
.then(r => r.json())
.then(data => console.log('bridge:', data))
.catch(()=> console.warn('Bridge not running'))
When Bridge is required
Modern browsers are moving towards WebHID and WebUSB, but not all stacks are consistent. Trezor Bridge ensures a stable, cross-browser experience for web apps that integrate with Trezor devices — especially helpful in enterprise setups or where legacy browser support matters.
Frequently asked questions
Yes — the Bridge project and its components are open source. Inspect code and build instructions on the Trezor repositories.
Trezor Suite connects directly to devices and may not require Bridge on all platforms; however Bridge remains the recommended, supported connector for web-based integrations.
Bridge includes an auto-update mechanism for minor releases. For major upgrades, download the installer from the official site and run it.