While it's not possible to carry out conclusive performance testing on VPN services due to the wide range of factors that can affect the speeds users see, we carry out speed tests to get a feel for how each service performs. We test all services using their clients' default settings unless changes are required for connection stability.
We run tests from a London-based connection that typically sees un-VPN'd speeds of over 59MB/s (472Mbit/s). We test multiple servers from each provider in three locations: the UK, the Netherlands and the USA and retest any anomalous results.
Our core tests include large file downloads via HTTP and FTP but note that these figures can only ever be a snapshot of performance at a single point in time, rather than being fully representative. We refer back to prior test results where relevant. Both are carried out on a Windows 10 PC with Windows Defender Enabled. We download reference FTP files from public servers around the world using FileZilla client. HTTP downloads - again from fast public servers - are carried out on Chrome and measured using the Chrono Download Manager extension.
While UK and Dutch endpoints can, from the best VPN services, match the speed of many internet connections without a VPN, connection speeds to the USA are typically far slower, with most VPNs clocking download speeds of less than 12MB/s (96 Mbit/s) on even the fastest of internet connections.
We also test whether we're able to view region-locked streaming video content from various streaming services, which have included Netflix, Crunchyroll and Shudder in the US, and All 4, Channel 5 and BBC iPlayer in the UK. Although Shudder does minimal region checking based on IP address, Netflix, Crunchyroll, iPlayer and All 4 work hard to identify and block IP addresses associated with VPN endpoints, so what works one month may not the next.