How to Prevent IP Address Leaks in 2026 (WebRTC, DNS, IPv6)

Key takeaways:

• An IP leak is when your real IP address is exposed even though you are using a proxy or VPN. The usual causes are WebRTC, DNS, and IPv6.
• Test first: run an IP, DNS, and WebRTC leak check while your proxy or VPN is on, then compare the result to your real IP.
• Fix the common causes: disable or control WebRTC, set a trusted DNS resolver, and disable IPv6 if your connection does not route it through the proxy.
• For automation and scraping, route requests through a reliable proxy and use remote DNS (SOCKS5h) so lookups do not fall back to your ISP.

The short answer: an IP leak happens when traffic slips around your proxy or VPN and reveals your real IP. The three usual culprits are WebRTC in your browser, DNS queries going to your ISP, and IPv6 traffic that is not tunneled. Test for each, fix the cause, then keep a few habits to stay protected. The table sums up the causes and fixes, then each section goes deeper.

What is an IP leak?

An IP leak is when your real IP address becomes visible to a website or service even though you are routing traffic through a proxy or VPN. The proxy is meant to present its own IP, but a side channel, such as a browser feature or a DNS query, exposes your real one.

Is it dangerous? On its own, a leaked IP reveals your approximate location and your ISP, and it can undo the privacy you set up a proxy to get. It is not the same as a password breach, but for account management, research, or data collection it can break your setup and link activity back to you. The good news is that leaks come from a short list of causes you can test and fix.

Common causes of IP leaks

Most real-world leaks trace back to the first three: WebRTC, DNS, and IPv6.

Most IP leaks come from the browser, DNS, or IPv6.

How to test for an IP leak

Testing takes a minute and tells you exactly what is exposed.

1. Note your real IP. With the proxy and VPN off, check your IP on any "what is my IP" page and write it down.
2. Turn on your proxy or VPN. Reconnect and reload the page. The IP shown should be the proxy's, not your real one.
3. Run a leak test. Use a reputable IP, DNS, and WebRTC leak checker and confirm that none of the results show your real IP or your ISP's DNS. If your provider gives you a tester, our guide on how to test proxies covers verification too.

If any test shows your real IP, your DNS resolver, or your IPv6 address, move to the matching fix below.

If no result shows your real IP or ISP DNS, you are protected.

How to fix each type of leak

Turn off or control WebRTC. In Firefox, open about:config, find media.peerconnection.enabled, and set it to false. In Chrome, Edge, and Opera, install a reputable WebRTC control extension and enable protection, since those browsers have no built-in toggle.

Set a trusted DNS resolver and flush the cache. Point your device or proxy at a trusted resolver instead of your ISP's, then clear the DNS cache so old entries do not linger:

ipconfig /flushdns

On macOS use sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder.

Disable IPv6 if it is not tunneled. If your proxy or VPN only covers IPv4, IPv6 traffic can leak around it. On Windows, open the adapter's properties and uncheck Internet Protocol Version 6. On macOS, set Configure IPv6 to Off in the network settings. Alternatively, use a setup that routes IPv6 too.

Use a kill switch. A kill switch blocks all traffic if the proxy or VPN drops, so nothing falls back to your ISP connection. Enable it wherever your tool offers one.

How to prevent IP leaks in email

Email is an overlooked leak vector. A message you send can carry your IP in the mail headers, and a message you open can report your IP back through a tracking pixel.

• Send through webmail. Major webmail providers relay your message through their servers, so the recipient does not see your home IP in the headers. Desktop mail clients are more likely to attach your originating IP.
• Block remote images. Turn off automatic image loading so tracking pixels cannot quietly record your IP when you open a message.
• Avoid unknown links. A link can log your IP the moment you click it, so treat links from unknown senders with care.

How to prevent IP leaks when scraping

Automation has its own leak risks, because a single misconfigured request can expose your real IP across thousands of calls.

• Resolve DNS through the proxy. Use SOCKS5h rather than plain SOCKS5 so the proxy resolves hostnames, which keeps DNS lookups off your ISP. See our guide on SOCKS5 and HTTP proxies for the difference.
• Handle IPv6 deliberately. Disable IPv6 in your client or use IPv6-aware proxies so requests do not slip out on an untunneled address.
• Use a reliable, well-sized pool. Rotating residential proxies spread requests across many real IPs, so no single address carries your whole footprint.

A trustworthy provider matters here. Proxy-Cheap offers residential proxies, ISP proxies, and datacenter proxies with 256-bit SSL, and you can compare the market in our roundup of the best proxy providers.

Best practices to stay protected

Run through these to keep your real IP private.

• Re-test for leaks after any network change, browser update, or new extension.
• Keep WebRTC controlled in every browser you use, not just your main one.
• Prefer tools with a kill switch and remote DNS resolution.
• For sensitive work, pair a proxy with proper application-level encryption, since a proxy does not encrypt traffic on its own. Our guide on proxy versus a VPN explains when each one fits, and how to hide your IP address covers the basics.