Why a VPN can change your speed test result

A VPN adds encryption and a relay route, so the test may use a longer or busier path.

When a VPN is active, traffic first travels to the VPN provider before continuing to the destination. That extra hop, encryption work, and the VPN server's current load can change download speed, upload speed, and latency. The effect depends on the VPN location, protocol, device, and network conditions.

If you want to understand the impact, test once with the VPN connected and once without it, using the same device and local connection. Only do this when it is safe for your work and privacy needs; a speed comparison is not a reason to bypass a required VPN.

The two results describe different routes. A slower VPN result does not by itself show that either the local internet service or the VPN is defective. Repeat comparable tests before contacting the relevant provider.