Depending on the operating system or device you're using, you have different connection methods and VPN protocols available. Please check the How to use page instructions, which are sorted by VPN Protocol (OpenVPN, L2TP, PPTP, SSTP and IKEv2, and SoftEther).
Basically, it does not matter which you choose, as trying all protocols is a good idea to get the most stable connection, more speed, bypass restrictions, etc.
For Windows, we recommend using Softether. We also support the below protocols on Windows:
IKEv2
L2TP
PPTP
SSTP
OpenVPN
For Mac, we support:
IKEv2
OpenVPN
L2TP
For Linux, we support:
OpenVPN
IKEv2
PPTP
L2TP
For Android, we support:
IKEv2
LimeVPN App based on OpenVPN
OpenVPN
L2TP
PPTP
For iOS, we support:
IKEv2
L2TP
OpenVPN
For routers, it actually depends on the routers. Some support multiple protocols and some only one.
Apart from these, we support Raspberry and all other major devices that support VPN.