Why VPNs Aren't Enough: The Reality of Browser Privacy

Here's a truth that VPN companies don't want you to hear: a VPN is just one piece of the privacy puzzle. And honestly? It's not even the most important piece.

Don't get me wrong — VPNs have their place. They encrypt your traffic and hide your IP from websites. That's useful. But here's the problem: your IP address is just one of hundreds of data points that can identify you online.

Think about it. When you use a VPN, you share the same IP address as thousands of other users. That's the whole point. But if your browser is leaking your real IP through WebRTC, your DNS queries are going through your ISP instead of the VPN, or your browser fingerprint makes you uniquely identifiable — the VPN didn't actually protect you.

WebRTC: The Leak Your VPN Can't Stop

WebRTC (Web Real-Time Communication) is a technology that lets browsers do video calls, voice chat, and peer-to-peer file sharing. Cool stuff. But it has a nasty side effect: to establish direct connections, it needs to know your real IP address.

Even when you're connected to a VPN, WebRTC can bypass the VPN tunnel and reveal your actual IP address. This happens because WebRTC uses a protocol called STUN/TURN to discover your network configuration — and this discovery process happens outside your VPN connection.

The fix is simple: disable WebRTC in your browser settings or use an extension that blocks WebRTC leaks. Our WebRTC test checks if you're vulnerable.

DNS: Your Browsing History on Display

Every time you visit a website, your computer asks a DNS server "what's the IP address for example.com?" This happens before the actual connection. If your DNS queries go through your ISP instead of your VPN, your ISP knows every website you visit — VPN or not.

Most VPNs route DNS through their own servers. But sometimes the configuration fails. Sometimes your system falls back to ISP DNS during brief connection drops. Sometimes IPv6 DNS queries leak while IPv4 is protected.

Our DNS leak test sends queries to test servers and checks where they actually came from. If they came from your ISP's DNS servers instead of your VPN's, you have a leak.

Ad Blockers: Not All Protection Is Equal

Ad blockers are privacy tools, not just annoyance filters. The best ones block tracking scripts, analytics beacons, and fingerprinting attempts — not just visible ads.

But here's the thing: there's a massive range in effectiveness. Some blockers use outdated filter lists. Some have gaps in their coverage. Some have been compromised by advertising companies. (Yes, that's happened — Google has been paying ad blockers to whitelist certain trackers.)

Our ad blocker test loads known tracking scripts and checks which ones get through. We test against real-world trackers from Google, Facebook, Amazon, and dozens of lesser-known data brokers. You might be surprised what your blocker misses.

HSTS Supercookies: The Tracking That Never Dies

HSTS (HTTP Strict Transport Security) is a security feature that forces browsers to use HTTPS. Good thing, right? But security researchers discovered it can be abused to create persistent tracking identifiers.

Here's how it works: a tracker loads a unique pattern of subdomains. Some use HSTS, some don't. Your browser remembers which domains require HTTPS — and that pattern becomes a unique identifier. This identifier survives cookie deletion, private browsing, and even browser reinstallation in some cases.

Our HSTS supercookie demo shows you exactly how this works. Understanding the attack is the first step to defending against it.

The Complete Privacy Testing Strategy

Privacy isn't a single tool — it's a stack of defenses. Here's how our tests fit into a complete privacy strategy:

Each test takes seconds to run. Together, they give you a complete picture of your browser's privacy posture. Run them regularly — configurations change, software updates break things, and new vulnerabilities appear all the time.