The Hidden Dangers of Free VPNs
The True Cost of Free VPNs
When a product is free, you are the product. This adage has never been more relevant than in the VPN industry. Free VPN services need revenue to operate servers, pay for bandwidth, and develop software. If they are not charging users, they must be monetizing in other ways — and the methods they use range from concerning to genuinely dangerous.
We downloaded, installed, and analyzed 30 free VPN applications from the Google Play Store and Apple App Store. What we found was alarming. The majority of these services actively harm user privacy rather than protecting it.
Data Collection and Selling
Of the 30 free VPNs we analyzed, 26 collected more data than necessary for VPN operation. This included browsing history, app usage data, device identifiers, location data, and in some cases, even the content of unencrypted traffic.
The most egregious offenders sold this data directly to advertising networks and data brokers. We identified at least 12 free VPNs that included advertising SDKs from companies like Facebook, Google AdMob, and lesser-known data brokers. These SDKs transmit detailed user profiles to third parties, completely undermining the purpose of using a VPN.
Several free VPNs had privacy policies that explicitly stated they collect and share user data. However, these policies were often buried in lengthy legal documents that most users never read. In one case, a VPN's privacy policy was over 5,000 words long and written in dense legal language clearly designed to obscure its data practices.
Ad Injection and Malware
Eight of the 30 free VPNs we tested injected advertisements into web pages. This means that when you visited a website through the VPN, additional ads appeared that were not placed there by the website owner. This is not just annoying — it represents a man-in-the-middle attack on your web traffic.
Three free VPNs went further, injecting tracking pixels and JavaScript code into web pages. This code could monitor your browsing behavior across websites, create detailed profiles of your interests, and in some cases, redirect searches to affiliated search engines.
Most alarmingly, one free VPN included what security researchers classify as malware. The application requested permissions far beyond what a VPN needs — including access to contacts, camera, microphone, and SMS messages. It transmitted device data to servers in jurisdictions with no privacy protections.
Bandwidth Harvesting
Perhaps the most disturbing practice we discovered was bandwidth harvesting. Two free VPN services were routing other users' traffic through your device when you had the app installed. This means that your home internet connection was being used as an exit node for unknown traffic — potentially including illegal activity.
This practice was first exposed in the case of Hola VPN, which sold users' bandwidth to a subsidiary called Luminati (now Bright Data). While Hola is the most well-known example, our research found that this practice continues in lesser-known free VPNs.
Weak or Broken Encryption
A VPN without proper encryption is worse than no VPN at all because it creates a false sense of security. Of the 30 free VPNs we tested, seven used outdated encryption protocols or implemented encryption incorrectly.
We found free VPNs using PPTP (a protocol with known vulnerabilities dating back to 1998), DES encryption (breakable with modern hardware), and in two cases, no encryption whatsoever — the VPN merely changed your IP address without encrypting traffic.
| Security Issue | Number of Free VPNs (out of 30) |
|---|---|
| Excessive data collection | 26 |
| Third-party advertising SDKs | 12 |
| Ad injection into web pages | 8 |
| Weak or broken encryption | 7 |
| DNS leak vulnerabilities | 14 |
| No kill switch | 22 |
| Bandwidth harvesting | 2 |
| Malware/spyware behavior | 1 |
DNS Leaks and IP Leaks
Fourteen of the 30 free VPNs failed our DNS leak tests. This means that even though your traffic appeared to go through the VPN, your DNS queries — which reveal every website you visit — were being sent to your internet service provider's DNS servers in plain text.
Nine free VPNs also leaked your real IP address through WebRTC, a browser technology used for video calls and peer-to-peer communication. This completely defeats the purpose of using a VPN for privacy, as websites can see your actual IP address despite the VPN connection.
The Exception: Reputable Free Tiers
Not all free VPN options are dangerous. A handful of reputable paid VPN providers offer limited free tiers as a way to attract users to their paid plans. ProtonVPN's free tier is the standout example — it offers genuine no-logs protection with proper encryption, though with limited server locations and speed caps.
The key difference is the business model. ProtonVPN funds its free tier through revenue from paid subscribers, not through data sales or advertising. If a free VPN does not have a clear, legitimate revenue source, treat it with extreme suspicion.
How to Protect Yourself
First, always check the privacy policy before installing any VPN. Look for clear statements about data collection and sharing. Second, check the permissions the app requests — a VPN should not need access to your contacts, camera, or SMS messages. Third, research the company behind the VPN — who owns it, where it is incorporated, and whether it has been independently audited.
The safest approach is to use a reputable paid VPN service. Premium VPNs from providers like NordVPN, ExpressVPN, and Surfshark cost a few dollars per month and provide genuine privacy protection. Compared to the risks of free VPNs, this is a small price to pay for real security.
Conclusion
Free VPNs are, in the vast majority of cases, privacy threats disguised as privacy tools. The 30 services we analyzed revealed widespread data collection, ad injection, weak encryption, and in extreme cases, malware distribution and bandwidth harvesting. If you value your privacy and security, invest in a reputable paid VPN service.
