Welcome to the ExpressVPN Digital Security Lab


Our goal at ExpressVPN is to help build a safe, private, and open internet that empowers people around the globe.

One of the tools we employ in pursuit of this goal is high-quality research. Before we can successfully approach a problem or threat, it is vital to have an in-depth understanding of it. This is where the Digital Security Lab fits in.

With a clearer perception of cyber challenges and a more diverse body of knowledge, we can all better prepare for, mitigate, and solve issues that threaten global digital rights. At the Digital Security Lab, we focus on real-world problems with a broad impact in the areas of:

  • Digital privacy

  • Cybersecurity

  • Access to knowledge

  • Information flows

Ultimately, we want to answer a basic but crucial question: How can we protect and expand our rights, including to privacy and security, in an increasingly connected world?


The ExpressVPN Digital Security Lab aims to empower consumers with useful information about their privacy, security, and rights online. We do that by:

ExpressVPN Digital Security Lab Mission

Advancing public understanding of the online landscape.

ExpressVPN Digital Security Lab Mission

Investigating privacy harms, producing actionable reports about security issues, and providing the guidance consumers need to better safeguard their digital lives.

ExpressVPN Digital Security Lab Mission

Expanding the reach of research and breaking down complex technical problems into results that are accessible to everyone.

Sean O'Brien - Principal Researcher at ExpressVPN Digital Security Lab.


Sean O’Brien is Principal Researcher at the Digital Security Lab, an initiative by leading privacy and security company ExpressVPN. As leader of the ExpressVPN Digital Security Lab, he tackles real-world threats to online privacy, security, and information access through the application of focused, original research.

Sean founded and leads Yale Privacy Lab, an initiative of the Information Society Project at Yale Law School, and is a Visiting Fellow at Yale University, where he has been a leading voice on digital rights for the past seven years. He was previously a Lecturer for Cybersecurity, the first course on the topic at Yale. Sean is also the Head Tutor of Oxford Cyber Security for Business Leaders, a program of the Saïd Business School at the University of Oxford.

His work has been featured by the Associated Press, The Guardian, Wired, Fast Company, Vice, and many more.


These are some of the research topics we are currently pursuing:

  • Mobile app privacy

  • IoT security issues

  • Proximity tracking and location surveillance

  • Censorship, internet filtering, and connectivity

ExpressVPN Leak Testing Tools

Rigorous, regular testing is key to ensuring a VPN service protects against leaks. As part of our investment into user privacy and security, ExpressVPN has developed an extensible suite of leak testing tools designed for both manual and automated regression testing.

While these tools were built to be used internally, we came to recognize they could be beneficial to improving privacy and security across the VPN industry as a whole. We have thus released them as Free and Open-Source Software (FOSS), enabling anyone to assess their risk of leaks and evaluate VPNs, as well as help the entire VPN industry raise its privacy and security standards.

These tools currently test for a number of different types of leaks, including:

  • IP address leaks

  • IP traffic leaks

  • DNS leaks

  • WebRTC leaks

  • BitTorrent leaks

  • Leaks resulting from unstable network connections

  • Leaks resulting from VPN servers being unreachable

Leak Testing Tools.

ExpressVPN will continue to evolve these tools and release new ones in the future. The case studies below provide in-depth investigations into each scenario, explaining how they could impact your privacy and security, as well as outlining how you can use the ExpressVPN Leak Testing Tools to evaluate your VPN’s effectiveness.

Learn more about the tools and how to use them: Leak Testing Tools

You can also download the tools from Github.

Online leak tests

For certain types of leaks, you can conduct simple tests with the following leak test pages developed by ExpressVPN:

Get in touch

We welcome researchers, academics, developers, and others to join us in our effort to improve online privacy and security. If you’d like to collaborate or speak to our research team, please drop us a line at digital-security-lab@expressvpn.com.