Securely bridging your browser with your Trezor hardware wallet
The Trezor Bridge is a small software layer that acts as a browser-to-device connector, enabling modern browsers to communicate securely with Trezor hardware wallets. It ensures that your transactions, signatures, and wallet interactions go through a protected local channel rather than exposing sensitive flows to web servers or browser extensions.
Historically, browser extensions were used to connect wallets to web applications, but those approaches became constrained by browser policies and security models. Trezor Bridge solves this by opening a local port on your machine (loopback interface) and letting web interfaces talk to your device securely via that channel.
In this overview, we will explore why Trezor Bridge is needed, how it works under the hood, what security considerations matter, how to install it, supported browsers and operating systems, troubleshooting tips, and frequently asked questions.
When you install Trezor Bridge, it listens on a local port (for instance, 127.0.0.1:21325 or similar) only on your own machine. Browser-based dApps (decentralized applications) or wallet web interfaces can query that port via standardized API calls. When a dApp sends a command (e.g. "get public address" or "sign transaction"), Bridge receives it, validates it, and forwards it on USB (or WebUSB) to the actual Trezor hardware.
Modern browsers (Chrome, Firefox, Edge, Brave) can make HTTP or WebSocket requests to localhost. The Trezor web interface (or dApps that integrate Trezor support) embed corresponding JavaScript code that targets local endpoints Bridge exposes. That way, your browser doesn’t need a direct driver or extension — Bridge handles all USB + cryptographic logic.
Trezor Bridge falls back gracefully: if a direct WebUSB connection is possible, it may use that; otherwise, it routes through the local port. This architecture provides better resilience across environments (e.g. browser updates or driver conflicts).
Because Bridge binds to the loopback interface, only processes on your own computer can talk to it. Remote hosts cannot reach it. This local-only access mitigates external network risk.
Every request sent to Trezor hardware must be approved by the user via the device interface. Bridge cannot sign or approve transactions on its own. The hardware acts as final arbiter.
Bridge publishes cryptographically signed releases. Always verify you have the correct official version. Using an outdated or tampered version may put you at risk.
Bridge runs with minimal privileges. It doesn’t require full admin rights (except when installing drivers on some OSs). It also doesn’t expose file‑system or other device access to web content.
Bridge supports Windows (7 / 8 / 10 / 11), macOS (10.13+), and many Linux distributions. Most mainstream browsers (Chrome, Firefox, Edge, Brave) on these OSes are supported. Always check the official Trezor site for the latest compatibility.
If your browser doesn’t connect:
Trezor Bridge is a local “middleware” service that connects your web browser and Trezor hardware wallet by listening on a local (loopback) port. Because modern browsers limit direct USB access and deprecated many extension-based models, Bridge enables secure communication without exposing your device to external networks. It ensures compatibility, security, and seamless integration.
Trezor Bridge works on Windows (7, 8, 10, 11), macOS (10.13+), and many Linux distributions. Supported browsers include Chrome (and Chromium-based), Firefox, Edge, Brave, and others. Always refer to Trezor’s official site for the latest compatibility list.
Yes, running the official Trezor Bridge is considered safe. It’s designed to bind only to the local interface (not externally accessible), and every sensitive operation (e.g. signing transactions) must be manually confirmed on the Trezor device. To avoid risk, always download Bridge from the official Trezor source and verify its signature.
In some environments (corporate networks, hardened systems), `localhost` traffic might be blocked or restricted. To resolve this, allow `127.0.0.1` and `localhost` in firewall or browser settings. You may also whitelist the ports used by Bridge (commonly 21325 or 21324, though these might vary). If still blocked, consider using another supported browser or adjusting OS network rules.
Yes, updating Bridge ensures security patches, compatibility with browser updates, and new features. You can check for new versions on the official Trezor website. Some versions may auto‑update or prompt you. Always verify new installers’ cryptographic signatures before installing.
Below is a more technical walkthrough of what happens when you connect a Trezor with Bridge and a web wallet:
Bridge might also implement queuing or multiplexing logic to handle simultaneous requests, timing out stale ones, and ensuring that device removal or disconnection is handled gracefully.
Note: Bridge does not store private keys or seed phrases — those remain safely within Trezor hardware at all times.
The **Trezor Bridge — Browser to Device Connector** is a critical component in ensuring you can securely interact with your Trezor hardware from a browser environment. By acting as a local intermediary, it provides both compatibility and safety without sacrificing user convenience.
With proper installation, configuration, and updates, Bridge ensures that your wallet interactions remain secure, private, and reliable — while modern browsers evolve and restrict direct hardware interfaces. Whether you’re accessing dApps, signing transactions, or managing your cryptocurrency, Bridge helps make that experience smooth and trustworthy.