Introduction

The security of cryptocurrency hinges on control of private keys. Hardware wallets like Trézor keep those keys offline in a dedicated, tamper-resistant device and require physical confirmation to perform cryptographic operations. As the Web3 ecosystem grows, users increasingly expect to interact with decentralized applications (dApps) and web wallets directly from a browser. Modern browsers, however, have limited or inconsistent direct USB support and have moved away from plugin models that once enabled hardware wallet connectivity.

Trézor Bridge® fills that gap. It is a lightweight desktop service that runs locally, creates a secure communication channel between the browser and your Trézor device, and ensures that all signing and key-related operations occur on-device. Bridge is intentionally minimal: it relays messages but never stores keys or performs signing itself. The result is a predictable, cross-platform workflow that preserves hardware-backed security while enabling practical Web3 access.

What is Trézor Bridge®?

At its core, Trézor Bridge® is a local proxy service. It exposes a local endpoint (for example, using the loopback address) that browser-based applications can call. When a dApp or the web version of Trezor Suite requests a signature or device data, the browser communicates with Bridge. Bridge forwards that request to the connected device over USB, the device shows a human-readable prompt, you confirm the action on the device, and Bridge returns the signed result to the browser. Crucially, Bridge itself never has access to your private keys, recovery seed, or passphrase.

Design goals

• Local-first security: Keep communication on your machine; do not route sensitive payloads through cloud services.
• Plugin-free compatibility: Avoid fragile browser plugins and provide a stable endpoint across Chrome, Firefox, Brave, Edge, and others.
• Minimal attack surface: Purpose-built as a transparent relay without persistent storage of secrets.
• User control: Require explicit on-device confirmation for every sensitive action.

How Trézor Bridge® Works — Step by Step

The user workflow with Bridge is intentionally simple and verifiable. Understanding this flow clarifies why Bridge is safe and how to use it properly.

1. Browser request: A web page or dApp requests access to the hardware wallet to read an address, request a signature, or perform a transaction.
2. Local relay: The browser calls the local Bridge endpoint. Bridge receives the request and forwards it to the connected Trézor device over USB.
3. On-device verification: The Trézor displays transaction details, contract data, or address information on its screen in a readable format for verification.
4. Physical confirmation: You confirm or reject the action by pressing the device buttons. If you confirm, the device performs the signing operation internally.
5. Return path: The signed data is returned to Bridge, which relays it back to the browser. The browser then broadcasts the transaction or completes the requested operation.

Every sensitive cryptographic operation remains inside the hardware device. The browser and Bridge are facilitators only; they cannot sign transactions without your explicit on-device approval.

Installing Trézor Bridge®

Installation is quick and user-friendly. Always download Bridge from the official Trézor website and verify you have the correct operating system package. Below are the typical steps for most users.

Step-by-step

1. Download the installer: Choose the Bridge package for Windows, macOS, or Linux from the official downloads page.
2. Run the installer: Follow the operating system prompts. On macOS, you may be asked to approve a system extension in Security & Privacy.
3. Connect your device: Use a data-capable USB cable; some charging cables do not support data transfer.
4. Open a supported site: Visit Trezor Suite Web or a compatible dApp. Bridge should automatically make the device available to the browser.

Web3 Compatibility and dApp Use

Trézor Bridge® enables secure access to a wide range of Web3 activities: interacting with decentralized exchanges, signing NFT transactions, participating in on-chain governance, or connecting to wallets and explorers. When a dApp requests a signature, Bridge relays the request and the device displays the exact contract data. Users should always verify recipient addresses, amounts, and contract actions on the device before approving. Where possible, prefer typed-data signing (EIP-712) or other structured signing formats that present clearer context for what you are signing.

Practical guidance

• Use a low-value test account when trying unfamiliar dApps.
• Be cautious with "infinite approvals" and consider revoking allowances you no longer need.
• Use passphrases (hidden wallets) if you require account separation or deniability.

Troubleshooting Common Bridge Issues

Most connection problems are environmental—USB cables, browser state, or OS permissions. Here are common issues and fixes:

• Device not detected: Restart the browser, check that Bridge is running (system tray / background service), reconnect the cable, or try a different USB port.
• Faulty cable or hub: Use a high-quality data cable and avoid unpowered USB hubs.
• Security software interference: Temporarily whitelist Bridge in antivirus/firewall tools to test connectivity.
• macOS permission prompts: Approve Bridge or system extensions under System Settings → Privacy & Security.
• Linux udev rules: Install recommended udev rules so non-root users have USB access to the device.

If issues persist, consult official troubleshooting resources and gather logs for diagnostic help.

Developer Notes — Integrating with dApps

Developers building dApp integrations should rely on Bridge as a predictable local endpoint. Important best practices:

• Present clear, human-readable transaction and contract summaries in your UI to help users compare the browser view with on-device details.
• Support widely-used signing standards (EIP-155, EIP-712) to improve clarity and compatibility across wallets.
• Test across major browsers and operating systems; browser security changes occasionally require updates to how Bridge is invoked or used.
• Encourage users to verify the device screen and to test with small-value transactions on unfamiliar dApps.

Security Best Practices

While Bridge is secure by design, strong user habits are essential to preserve asset safety. Follow these recommendations:

• Always download Bridge and firmware updates from official sources.
• Keep your device firmware and Bridge installation up to date to receive security patches.
• Use a strong PIN and consider enabling a passphrase for an added security layer.
• Never enter your recovery seed into a computer or browser—store it offline in a secure place.
• Always verify transaction details on the device screen; if anything looks incorrect, cancel the operation and investigate.
• Avoid performing high-value operations on shared or public computers.

Conclusion

Trézor Bridge® is a foundational component for anyone using a Trézor hardware wallet to interact with the web. It restores reliable, local, plugin-free connectivity between browsers and hardware devices while maintaining hardware-level security guarantees. By keeping communication local and requiring on-device confirmation for all sensitive actions, Bridge enables a secure and usable Web3 experience for individuals and developers alike.

Install Bridge from official sources, follow the recommended troubleshooting steps when problems arise, adopt the security best practices outlined here, and always verify every transaction on your device. With Bridge in place, you can confidently use web-based wallets and dApps while ensuring your private keys remain under your control.