How to Fix a WebRTC Leak in Firefox

Using a VPN does not automatically guarantee that your real IP address is completely hidden.

Even when connected to a VPN, Firefox may expose network information through WebRTC, allowing websites to discover your real IP address, local network addresses, or IPv6 connectivity details.

If a WebRTC leak test reveals your ISP-assigned IP address, your online privacy may be compromised despite having an active VPN connection.

🚀 Test for WebRTC Leaks

Before making any changes, check whether Firefox is currently exposing your real IP address.

Run WebRTC Leak Test →

What Is a WebRTC Leak?

WebRTC (Web Real-Time Communication) is a browser technology used for voice calls, video conferencing, peer-to-peer communication, screen sharing, and real-time collaboration tools.

To establish direct connections, browsers use STUN requests to discover available network interfaces and IP addresses.

In some situations, websites can access this information and identify:

❌ Your public ISP IP address

❌ Your IPv6 address

❌ Local network addresses

❌ Information that bypasses your VPN tunnel

This is known as a WebRTC leak.

Why VPN Users Should Care

Many people use VPNs to protect privacy, hide their location, prevent tracking, secure public Wi-Fi connections, and access geo-restricted content.

If Firefox exposes your real IP through WebRTC, websites may still be able to identify your actual network connection even though your VPN appears active.

Step 1: Open Firefox Advanced Configuration

In the Firefox address bar, enter:

about:config

Click Accept the Risk and Continue if Firefox displays a warning.

Step 2: Locate the WebRTC Setting

Search for:

media.peerconnection.enabled

This preference controls Firefox's WebRTC functionality.

Step 3: Disable WebRTC

Double-click the setting and change:

true

to:

false

This completely disables WebRTC within Firefox.

Step 4: Restart Firefox

Close all Firefox windows and restart the browser.

The new setting should take effect immediately.

Verify That the Leak Is Fixed

After restarting Firefox, run another WebRTC leak test.

A properly configured browser should show:

✅ No exposed ISP IP address

✅ No leaked public IPv4 address

✅ No leaked IPv6 address

✅ Only the VPN IP address visible

Test your browser here:

WebRTC Leak Test

Why You Should Also Run a VPN Check

A WebRTC leak test and a VPN detection test measure different things.

A browser may stop leaking your real IP address while websites can still identify that you're using a VPN.

Run both tests for a complete privacy assessment:

✅ WebRTC Leak Test checks IP exposure

✅ VPN Check detects VPN usage

✅ Combined testing validates your privacy setup

Check your VPN status:

VPN Check Tool

What If Your Real IP Still Appears?

Verify your VPN connection is active
Enable VPN leak protection features
Disable or secure IPv6 traffic
Check conflicting browser extensions
Update Firefox

Additional guides:

Does Disabling WebRTC Affect Browsing?

For most users, disabling WebRTC has no impact on normal browsing.

However, some services rely on WebRTC:

Google Meet
Microsoft Teams (browser version)
Discord Web
Browser-based video calling platforms

If these services stop working correctly, you may need to temporarily re-enable WebRTC.

🚀 Verify Your VPN Privacy Setup

Check whether websites can detect your VPN and confirm that your browser is no longer exposing your real IP address.

Run VPN Check →

Final Checklist

✅ Disable WebRTC in Firefox

✅ Restart Firefox

✅ Run a WebRTC leak test

✅ Verify your VPN connection

✅ Check for IPv6 leaks

✅ Run a VPN detection test

✅ Confirm your real IP address is hidden

A VPN can only protect your privacy if your browser is not leaking identifying information. Running both a WebRTC leak test and a VPN detection test helps ensure your setup is working exactly as expected.