What is Trezor Bridge?
Trezor Bridge is a small helper application that runs on your computer and securely mediates communication between your web browser (or desktop apps) and your Trezor Hardware Wallet®. Because web browsers cannot talk directly to a USB device in a standardized way across platforms, Trezor Bridge provides a local, secure channel so your browser-based wallet interface can sign transactions and manage accounts while your private keys remain on the Trezor device.
Key responsibilities
- Expose a local endpoint that browser wallet UIs can call.
- Forward requests to the Trezor device over USB in a safe, documented protocol.
- Keep cryptographic operations on the device — Bridge only forwards commands and responses.
Why not use browser-only USB?
Native WebUSB support exists in some browsers, but it’s uneven across platforms and can create UX and compatibility problems. Bridge provides a consistent cross-platform experience for all major operating systems and web wallets.
How Trezor Bridge protects your keys
Trezor Bridge intentionally never stores or transmits your seed, PIN, or passphrase. Its role is only to pass messages between your device and authorized clients. Security properties include:
Security guarantees
- Isolated private key usage: All signing happens inside the Trezor device — Bridge never performs cryptographic signing.
- Local-only endpoint: Bridge exposes a localhost API so requests originate from your machine and cannot come from remote servers.
- Updateable and auditable: Bridge releases are signed and published so users can verify authenticity.
What Bridge does not do
Bridge does not manage keys, transmit seeds to the network, or function as a remote backup. If someone gains access to your computer, Bridge alone does not give them control of your coins — they would need physical access to your Trezor or your PIN/passphrase.
Installing and updating Trezor Bridge
Always download Bridge from official sources and verify the release when possible. Below are compact, platform-specific steps and links.
Quick install (Windows / macOS / Linux)
- Visit the official download page (link list below).
- Choose the package for your OS and run the installer.
- Allow the app to run when your browser prompts for permission.
Automatic updates
Bridge can notify you of updates. For security, accept updates only from the official provider and verify signatures if you maintain stringent security practices.
<!-- example: launching a Bridge request (conceptual) -->
fetch('http://127.0.0.1:21325/', {
method: 'POST',
headers: {'Content-Type':'application/json'},
body: JSON.stringify({method:'getFeatures', params:{}})
})
.then(res => res.json()).then(console.log);
Troubleshooting common Bridge issues
1. Browser can’t detect Trezor
Ensure Bridge is running and up-to-date. Reconnect the device, try a different USB cable or port, and confirm the browser isn’t blocking local connections.
2. “Bridge not found” errors
Most often caused by a missing or outdated Bridge process. Reinstall Bridge from the official page, restart your browser, and check any firewall or antivirus settings that may block local endpoints.
3. Permission or blocking by security tools
Some corporate or third-party security suites block localhost servers. If you suspect this, temporarily allow Bridge through the firewall for the loopback address (127.0.0.1) and test again.
Advanced diagnostics
- Check the Bridge process in your system process list.
- Look for logs or verbose output from Bridge (if enabled).
- Confirm the device works on another computer to rule out hardware failure.
Best practices and security checklist
Follow these rules to reduce risk when using Trezor Bridge and your Hardware Wallet®:
Before use
- Download Bridge only from official sources.
- Verify installer signatures if you can.
- Keep your OS and browser patched.
During use
- Confirm every signing request on your physical device before confirming.
- Never enter your seed words into a computer or browser.
- Use a secure passphrase and a strong PIN on your Trezor.
After use
- Keep Bridge updated and remove it if you no longer use the device.
- Back up your recovery seed in a safe, offline location.
Official resources & downloads
Below are official pages where you can download Bridge, read documentation, check release notes, and find support. Each link is styled in the official accent color for quick recognition.
Final thoughts
Trezor Bridge is a small but critical piece of infrastructure that makes working with your Trezor Hardware Wallet® convenient and cross-platform while preserving the core security model: private keys never leave your device. By downloading Bridge only from official sources, verifying updates, and following the security checklist above, you can use web wallets and desktop apps with strong confidence.
Quick checklist
- Download Bridge from official pages above.
- Keep both the device and Bridge updated.
- Always confirm signatures on the hardware display.
- Never type your recovery seed into a computer.