Why Is My Internet Slower With a VPN?
Some performance loss with a VPN is normal because traffic is encrypted and takes an additional route. The size of the slowdown depends on the server, protocol, device, network and current congestion.
A VPN adds work and distance
Your device encrypts traffic and sends it to a VPN server before it continues toward its destination. A distant or busy VPN server can increase latency, while encryption and software processing can limit throughput on some devices.
How to test the difference fairly
Run a connection-quality test with the VPN disconnected, then connect to the VPN server you actually plan to use and repeat the test. Keep the same device and connection type. Compare download, upload, idle latency and loaded latency rather than focusing on only one large speed number.
Ways to improve VPN performance
Try a geographically closer server, another server in the same region, or a modern protocol supported by your VPN. Use wired Ethernet or strong Wi-Fi when possible, close heavy downloads, and confirm that the slowdown is actually caused by the VPN rather than congestion elsewhere on the network.