If you want to stream HD video streams you will need approximate download speeds of between 5 and 8 Mbps. This goes up to 25 Mbps if you want to stream 4K UHD content.
The VPNs we have recommended in this guide all have servers that far exceed the speed you need to watch 4K TV streams. However, it is important to remember that your ISP controls your internet speed.
Even the fastest VPN will slow down your internet slightly when it encrypts your data and routes it to the remote VPN server location. The nice thing about a fast VPN is that it will not slow you down very much, meaning that you still have similar speeds to those you usually get from your ISP.
The only caveat is that if you only pay your ISP for very slow internet, the VPN will still reduce those speeds slightly. So it is important to understand how much overhead you have and how a VPN will affect your speed if you already have very slow internet.
We recommend that you check your speeds without a VPN, and if you have speeds of above 30 Mbps or more, you should be able to enjoy 4K videos even while connected to the VPN. For HD videos, we recommend that you have a base speed of 10 Mbps or more without the VPN.