Surfshark is the best fast VPN choice for a modern Asus router for most users, particularly if your router supports Asus VPN Fusion with WireGuard. ProtonVPN is another strong WireGuard option on compatible RT-AX-series AsusWRT routers, while NordVPN has one of the clearest Asus VPN Fusion setups but currently relies primarily on imported OpenVPN profiles in its official AsusWRT instructions.
The important limitation is that the VPN provider is only half of an Asus router VPN setup. Router model, AsusWRT firmware version, VPN Fusion support, protocol, CPU performance, and whether you route every device or only selected clients can have a larger effect on real throughput than the speed you see from the same VPN’s Windows or mobile app.
