Trezor Bridge Firewall & Antivirus Conflicts: What You Need to Know

If you're setting up or using a Trezor hardware wallet, you're likely relying on Trezor Bridge to establish a secure connection between your device and your computer. While it's an essential component for Trezor’s functionality, conflicts with firewalls and antivirus software can cause frustrating issues, especially for first-time users. Here’s what you need to know.

What Is Trezor Bridge?

Trezor Bridge is a background service that allows communication between your web browser and Trezor hardware wallet. It's designed to replace older communication methods like browser extensions and is necessary for accessing Trezor Suite via a web interface.

Common Symptoms of Conflicts

When a firewall or antivirus program interferes with Trezor Bridge, you might encounter symptoms such as:

• Trezor Suite not recognizing your connected device
• Browser failing to establish a secure session with your Trezor
• "Trezor Bridge not running" messages, even when it's installed
• Random disconnects or inability to initiate firmware updates

These issues usually stem from your security software misidentifying Trezor Bridge as suspicious activity.

How Firewalls Cause Problems

Firewalls—especially third-party ones—often block unfamiliar ports or local connections by default. Since Trezor Bridge uses local network communication (typically via localhost), it may get flagged or blocked unintentionally.

To address this, ensure your firewall allows the following:

• Localhost (127.0.0.1) communication
• Trezor Bridge executable as a trusted application
• Inbound and outbound traffic on port 21325 (commonly used by Trezor Bridge)

Antivirus Interference

Some antivirus software includes "real-time protection" features that monitor background processes for suspicious behavior. If the antivirus flags the Bridge service as a potential threat, it may quarantine the app or prevent it from running altogether.

Typical solutions include:

• Adding the Trezor Bridge folder to your antivirus's exception list
• Temporarily disabling real-time protection during setup
• Ensuring the installer is downloaded from the official Trezor source

Operating System Considerations

On Windows, User Account Control (UAC) might prompt you during the installation. Granting permissions is crucial for Trezor Bridge to function properly.

On macOS, additional privacy permissions may be needed, especially if you're running a security-focused third-party firewall. You may need to manually allow the app through System Settings under Security & Privacy.

Best Practices for a Smooth Experience

1. Install Trezor Bridge before connecting your device.
2. Use official software and keep it updated.
3. Whitelist the Trezor Bridge process in both your antivirus and firewall.
4. Avoid running multiple security tools simultaneously, as this increases the chances of conflict.
5. Restart your browser and computer after making changes to your firewall or antivirus settings.

Final Thoughts

Trezor Bridge is a vital tool for securing your cryptocurrency transactions, but like many background services, it can trip alarms in well-meaning security software. Taking a few minutes to configure exceptions can save hours of troubleshooting. Understanding how your firewall and antivirus interact with it will ensure your Trezor experience remains seamless and secure.