Trezor Bridge — Secure Connection for Your Trezor

What is Trezor Bridge?

Trezor Bridge is (or, historically, was) a small, local background service developed by the Trezor team that allowed web applications and desktop software to communicate with a Trezor hardware wallet over USB using a standard interface. It was the glue connecting your browser or Trezor Suite to the secure device itself.

Why a separate Bridge program?

Browsers sandbox web pages and have limited direct USB access for security reasons. Bridge provided a controlled local endpoint so the browser could send commands (like “get address” or “sign transaction”) to the Trezor without exposing USB traffic to arbitrary web pages.

Bridge responsibilities (high level)

Expose a local HTTP/HTTPS-like API to authorized apps.
Translate requests into USB/HID messages to the Trezor device.
Present a minimal, auditable surface area that could be verified and updated separately from browser security models.

How it worked — simplified flow

Typical flow for a web-based wallet or Trezor Suite:

App requests connection to local Bridge endpoint (localhost).
Bridge enumerates attached Trezor devices and forwards app requests to the correct device.
User confirms sensitive actions on the Trezor’s screen (PIN entry, confirm address, sign transaction).
Bridge relays signed data back to the app.

Security model and why on-device confirmation matters

Trezor’s security model is centered on keeping private keys off the host machine. Bridge only passes messages; the secret material never leaves the hardware. The device display, PIN and confirmation buttons create a trusted I/O channel between you and your keys.

Key security benefits

Isolated key storage: private keys stored inside the device.
Human-in-the-loop confirmations: transactions must be confirmed on the device itself.
Minimal attack surface: Bridge reduces direct USB complexity in browsers.

What Bridge does NOT do

Bridge does not — and cannot — extract your seed or private keys. It cannot sign actions without explicit approval on the device. That’s the whole point of hardware wallets: signing authority remains inside the device.

Installation, deprecation, and modern usage

Historically, users installed Trezor Bridge on desktop operating systems to interact with the Trezor hardware. Over time Trezor Suite became the recommended approach; some pages explain deprecation of standalone Bridge.

Install vs use Trezor Suite

The modern recommendation from Trezor is to use Trezor Suite (the official desktop/web companion app) which bundles secure communication paths and reduces reliance on a separate Bridge package. If you still use the standalone Bridge, check official guidance before installing or removing it.

Official resources & downloads: Always download Bridge or Trezor Suite from official sources (links at the end of this article).

Uninstalling Bridge

If you have Bridge installed and want to switch to Trezor Suite, follow the official removal instructions for your OS — macOS, Windows and Linux have specific uninstall steps.

Troubleshooting common Bridge issues

1. Device not detected

Check physical USB connection, try a different cable/port, and confirm Bridge/trezord process is running. On Linux make sure udev rules are present and the user has appropriate permissions.

Checks (quick)

Is the Trezor unlocked and displaying the home screen?
Is the Bridge/trezord process running? (Task Manager/Activity Monitor/System Monitor)
Try a different USB cable — charge-only cables often break data lines.

2. Browser can't connect

Confirm you are using a supported browser version. If you use a browser extension or privacy add-on, temporarily disable it to rule out interference. The modern path is to use Trezor Suite desktop app which streamlines connectivity.

3. Conflicting software

Other wallet software or leftover old installs can sometimes conflict with the Bridge. If you installed multiple Trezor helpers over time, uninstall older versions and follow the official reinstall guide.

Developer notes and integrations

For developers building integrations, Trezor provides repositories and development tools that document the expected communication patterns and APIs. If you plan to integrate Trezor support into a web app, refer to the official developer repositories and the recommended approach (WebUSB or Trezor Suite-backed flows).

Useful developer hints

Prefer official libraries (e.g., SDKs) rather than re-implementing low-level protocols.
Always verify firmware and measure compatibility with the target Trezor model.
Consider user prompts and clear guidance for installing Bridge or using Trezor Suite.

Privacy and security considerations

Although Bridge is a local service, best practice is to maintain a minimal and updated software stack. Keep Trezor firmware and any host-side software up to date. Review the vendor’s security pages and bug bounty information for the latest guidance.

What to watch out for

Phishing and fake Bridge packages

Only download Bridge or Trezor Suite from official domains. Attackers sometimes create lookalike sites that host malicious versions of wallet software. Verify signatures where possible.

Keep firmware & host software updated

Firmware updates often include security improvements. Always follow the official firmware update guidance and only update from the official Suite or repository channels.

Is Bridge still necessary?

As the Trezor ecosystem evolved, the team shifted users toward Trezor Suite and integrated communication paths. Many modern setups favor Trezor Suite (desktop or web) and WebUSB-enabled flows that reduce the need for a separately installed Bridge. Check official guidance for your device and OS.

When you might still encounter Bridge

Using older distributions or environments where Trezor Suite isn’t available.
Custom integrations or headless systems that rely on the trezord daemon.
Legacy documentation or workflows that have not yet transitioned.

Best practices — checklist

Before connecting

Download software only from official sources.
Inspect package signatures when available.
Use a data-capable USB cable and a reliable port.

While using

Confirm every transaction on the device display.
Keep sensitive backup phrases offline and air-gapped.
Use a device PIN and passphrase for extra protection when needed.

Maintenance

Keep Trezor firmware and host software up to date.
Uninstall deprecated standalone Bridge if recommended by official guidance.
Monitor official support channels for important advisories.

Conclusion

Trezor Bridge played an important role in securely connecting hardware wallets to host applications and browsers. As the ecosystem matured, official guidance moved users toward Trezor Suite and integrated flows that reduce the need for standalone Bridge installs. Whatever your setup, the most important rules remain: only use official software, verify downloads, confirm actions on-device, and keep firmware/software up to date.

Official links & references

Use the official documentation and repositories below for downloads, detailed guides and security information: