What is Trezor Bridge?
Trezor Bridge is a small background application that runs on your computer and exposes a local API that browsers and desktop wallets can use to talk to your Trezor device. Historically, hardware wallets used browser plugins or low-level USB access that varied by browser and platform. Bridge standardizes that communication and simplifies integration for developers while giving end users a reliable, cross-platform way to connect their devices.
How Bridge works (simple)
Local HTTP(s) gateway
Bridge typically listens on a local port (localhost) and accepts requests from trusted origins — these are the web pages and apps you authorize. When a site needs to interact with your Trezor device (for example, to request wallet addresses or sign a transaction), it sends a request to Bridge which forwards it securely over USB to the Trezor hardware. The device performs the cryptographic operation and returns the result back through Bridge to the requesting page.
Security model
Crucially, Bridge does not — and cannot — access your recovery seed. All private keys remain on the hardware device. Bridge is merely a conduit for messages. That said, Bridge enforces origin checks and user confirmations so that unauthorized pages cannot silently drain funds: every transaction must be confirmed on the device itself.
Installing Trezor Bridge
Installation is straightforward. Download the Bridge installer for your operating system, run it, and then open your browser or the Trezor Suite web app. The first time you connect your device after installation you'll be prompted to authorize the site. Below is a short example of the typical steps:
2. Connect your Trezor via USB -> Allow device unlock on the hardware
3. Open your chosen wallet interface -> Confirm connection requests on device
If you use a browser that supports WebUSB natively, Bridge is still recommended for wider compatibility and to avoid browser permission issues.
Common issues & fixes
1. Browser can't find device
Restart Bridge or reinstall it. Make sure no other wallet software is blocking USB, and that the cable and port are working. Try a different USB cable that supports data (some cables are charge-only).
2. Permission errors
Clear browser site data or explicitly remove stale authorizations. Confirm that you allow the specific website to access Bridge when prompted.
3. Stuck during firmware update
Follow the official recovery instructions provided by the vendor; do not interrupt a firmware update unless instructed. If a recovery is necessary, use the official recovery tool and follow the exact steps on the device's screen.
Best practices when using Trezor Bridge
- Always download Bridge from official sources — avoid third-party mirrors.
- Keep firmware and Bridge updated to benefit from security fixes and compatibility improvements.
- Use a quality USB cable and avoid hubs when possible; direct connections are more reliable.
- Verify transaction details on the device screen — never confirm operations you did not initiate.
- Keep your recovery seed offline — Bridge and any software can never and should never request your seed.
Privacy, security, and threat model
Trezor Bridge is designed with the assumption that the host computer may be compromised. Because the private keys never leave the device, an attacker with desktop access cannot trivially extract funds — however they can trick an unsuspecting user into approving malicious transactions by altering transaction details shown in software. That’s why the hardware device displays canonical details (recipient address, amounts, fees) and requires an explicit physical confirmation.
Additional security tips
- Always double-check addresses on the device's display — small fonts, copy-paste attacks and clipboard monitoring on the host machine are common attack vectors.
- Use passphrase protection (if you understand the caveats) to add another layer of security to the wallet.
- Consider using a dedicated clean machine for large-value transactions if you suspect your computer might be compromised.
For developers
Bridge exposes a clear local API that developers can interact with to build integrations. If you are integrating Bridge into a web wallet, always check the origin and handle errors gracefully. Provide clear instructions to end-users when device authorization is required — UX patterns for hardware confirmation make a big difference in reducing user errors.
Open-source implementations and SDKs exist to simplify integration — check the official developer documentation for the most current guidance.
Official resources & useful links
Always rely on official and reputable resources when downloading Bridge, reading support articles, or following recovery procedures. Below are ten official links that cover downloads, docs, support and community resources.
Conclusion
Trezor Bridge is the unsung utility that makes hardware wallets practical for modern web-based crypto workflows. It brings consistency across platforms, simplifies developer integration, and — when used correctly — preserves the strong security guarantees that hardware wallets provide. Follow the best practices in this guide: download from official pages, verify everything on your device, and keep both Bridge and your device firmware up to date. With those habits, Bridge will be a reliable, secure part of your crypto toolchain.