The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test connection speed
We test VPNs on a high-speed internet connection to see how likely they are to slow down your browsing experience.
How we test features and streaming
Whether the VPN has all the features you could need, plus whether it was able to connect successfully to streaming services.
How we test ease of use
How easy it is to install and configure the software.
How we test impact on computer performance
VPNs can be quite performance-hungry as they have to encrypt and decrypt all the data that leaves and returns to your device. We see whether it's likely to slow your computer down. A higher score means a lower impact.
How we test security
We check for common software bugs that could open up security holes, and we also ensure that data is not leaked between your computer and the VPN company's servers.
How we test privacy
We check whether VPN software connects to third-party services and which data is transmitted. 5 stars means data may be transmitted but is not uniquely associated with your device. 3 stars means data may be transmitted that can be traced back to your device, but not your individual VPN account. We also ensure there are no inappropriate permissions that allow VPNs to access more parts of your device than they really need.
How we test subscription clarity
How easy it is to disable automatic renewal and how clear the wording is when you attempt to cancel your subscription.