What is Trezor Bridge?
Trezor Bridge is a small background application created by SatoshiLabs that acts as a communication layer between your Trezor hardware wallet and desktop browsers or apps. Historically, it allowed web applications and local software to detect and communicate with a plugged-in Trezor device using a stable host-side interface — handling USB permissions, data routing, and protocol bridging so browsers didn’t need special native drivers or deprecated browser plugins.
Why a bridge?
Browsers intentionally restrict direct access to USB devices for security reasons. Bridge software provides a controlled, documented interface: it runs locally, listens on a loopback port, and mediates messages between the Trezor device and software such as Trezor Suite or compatible wallets. This keeps the low-level USB logic out of the browser and provides a consistent cross-platform experience.
Brief history
Introduced in 2018, Trezor Bridge solved compatibility problems across Windows, macOS and Linux and replaced older methods like browser plugin-based access. Over time, Trezor migrated many features into Trezor Suite and modern platform APIs — and the standalone Bridge has been officially deprecated in favor of integrated solutions inside Trezor Suite and other supported tooling.
How Trezor Bridge works (technical overview)
This section provides a non-trivial technical summary for curious users and implementers.
Architecture
At runtime, Bridge installs as a background service/daemon. It exposes a local HTTP/HTTPS endpoint on the localhost interface. Clients (for example, Trezor Suite web UI or third-party apps) send JSON-RPC style requests over this endpoint, and Bridge forwards those requests to the connected device via USB/HID or WebUSB where supported. Responses flow back the same way. This separation enables sandboxed apps to interact with hardware without requiring kernel-level drivers or browser plugins.
Supported transports
Bridge historically supported USB HID and WebUSB transports. On platforms or browsers where direct WebUSB access is unavailable or unreliable, Bridge provides a fallback by exposing the device through the local endpoint.
Versioning & compatibility
Trezor Bridge versions were designed to be backward compatible with a range of firmware releases. Nevertheless, compatibility depends on the device firmware and client software; when either side updates, it’s best to keep both client and firmware reasonably current.
Install & setup — step by step
Before installing Bridge, check whether you need it. Today Trezor Suite (desktop or web) is the recommended way to use Trezor devices — and modern Suite versions bundle or remove the need for a separate Bridge. If you are using older workflows or a specific third-party app that requires Bridge, follow the steps below.
Preparation
- Back up your recovery seed before connecting or upgrading anything. Never share the seed with anyone.
- Use only official downloads from trezor.io or links published by SatoshiLabs.
- Close browser windows that may be talking to your Trezor, and temporarily disable other wallet software while installing.
Windows
- Download the official Trezor Bridge installer from the official website.
- Run the installer as administrator and follow on-screen prompts.
- After installation, open Trezor Suite or the target app — your device should now be recognized.
macOS
- Download the
.dmgor package from the official site. - Open the package and follow the installer (you may be required to allow a kernel or security prompt depending on macOS version).
- If using modern macOS versions with stronger privacy controls, ensure Bridge is allowed to run in Security & Privacy settings if prompted.
Linux
Linux distributions vary. Bridge was historically available as a distribution package or tarball. For security and simplicity, prefer the Trezor Suite App or distribution-specific packages and follow the guides on the official docs site.
Tip
If a download page recommends switching to Trezor Suite or removing standalone Bridge, follow that recommendation — it reflects the current official guidance.
Security considerations
When tackling any software that interacts with hardware wallets, security posture matters. Bridge was carefully engineered, but like any software it has had historical vulnerabilities and received security patches. Here are a few practical points:
Use official sources
Only install Bridge or Suite from the official Trezor domains. Attackers frequently replicate download pages and distribute trojanized installers.
Keep software updated
Update Bridge, Trezor Suite, and your device firmware promptly. Security fixes for host-side tooling mitigate privilege escalation and other risks.
Known issues & CVEs
Historically, a few vulnerabilities have been assigned CVEs related to Bridge and related components. Treat these as a reminder to remove outdated standalone Bridge installations and to follow official deprecation guidance when present.
Attack surface
Bridge runs locally and listens on localhost. An attacker with local access could target the host application; therefore secure your computer, avoid running untrusted software as admin, and maintain good OS hygiene (patching, antivirus, disk encryption).
Troubleshooting common issues
Problems connecting a Trezor device can be caused by many small things — driver conflicts, outdated software, locked USB ports, or browser permissions. Here’s a checklist to diagnose and fix routine problems.
Checklist
- Ensure the cable and USB port are working (test with another cable or port).
- Confirm the device screen lights up and shows the model name when plugged in.
- Restart Trezor Suite (or the app) and your browser.
- Uninstall old/standalone Bridge if official guidance says so, then reinstall the recommended package or use Trezor Suite.
- Check OS security prompts: allow access where requested.
Advanced
If the device still isn’t recognized, collect logs (Trezor Suite provides diagnostics), search the official forums, or follow the support docs. Avoid sharing seed phrases or private data when asking for help.
Integration with Trezor Suite & the future
Trezor Suite is now the canonical official app for managing Trezor devices. As the platform evolved, SatoshiLabs integrated Bridge functionality into Suite and recommended deprecating the old standalone Bridge installers. This simplifies the user experience and reduces the number of moving pieces users need to update manually.
When you should still consider Bridge
If you're using a legacy third-party app that explicitly requires Bridge, or a custom workflow that cannot use Trezor Suite, a carefully maintained Bridge installation may be necessary. Otherwise, prefer Suite.
Frequently Asked Questions (FAQ)
Q1: Is Trezor Bridge required to use my Trezor?
A1: Not always. Modern users should default to Trezor Suite (desktop or web) which offers built-in communication paths. Standalone Bridge was historically required for browser-based interactions but has been deprecated in many contexts—check official guidance for your device and OS.
Q2: Where can I download Trezor Bridge?
A2: Always use the official Trezor website or the official Trezor Suite distribution. Avoid third‑party download mirrors and search-engine ads that mimic the download page.
Q3: I installed Bridge but nothing happens. What now?
A3: Reboot, test cables/ports, uninstall old versions, and ensure the target application is allowed to access the localhost endpoint. If problems persist, consult Trezor support and the official troubleshooting guides.
Q4: Is Bridge safe to run?
A4: When obtained from the official source and kept up-to-date, Bridge is reasonably safe. The greater risk is running outdated versions or installing binaries from untrusted sources.
Q5: Should I uninstall standalone Bridge?
A5: If the official documentation for your device or Suite indicates deprecation, follow the recommended uninstall steps. Removing deprecated software reduces attack surface and prevents compatibility problems.
Q6: How does Bridge handle passphrases or PINs?
A6: Bridge is only a transport layer — sensitive user input like PINs and passphrases are handled on the Trezor device itself (display and buttons) or by Trezor Suite's secure UI. Never type your recovery seed into a computer or browser.
Q7: Can I use Bridge with mobile devices?
A7: Mobile support depends on the mobile operating system and the way the Trezor device connects (USB-C, OTG, or Bluetooth where applicable). Trezor Suite mobile and modern mobile integrations aim to minimize the need for a separate Bridge app.
Q8: What are alternatives to Bridge?
A8: Use Trezor Suite, native WebUSB (where available), or wallet integrations that support direct hardware connectivity without a host-side Bridge. For advanced users, self-hosted tooling and libraries (like the official client libraries) can interface with devices using supported transports.
Q9: Where do I report a security issue?
A9: Use official channels listed on the Trezor website — security reports and coordinated disclosure methods are described in their security pages. Do not post sensitive technical details publicly before the vendor has had a chance to respond.
Q10: My corporate IT blocks Bridge — any suggestions?
A10: Work with your IT team. Because Bridge listens on localhost and uses USB, it may be blocked by strict policies. Consider using an approved workstation with Trezor Suite installed, or request a temporary exception for the required traffic. For high-security corporate rollouts, coordinate with security teams and adopt an enterprise control policy.
Official & helpful links (10 colorful quick-links)
These are curated links to official Trezor pages, guides, and community resources. Open in a new tab to keep this guide visible.