Why Hysteria2

The channel to the server is roughly the same for everyone. The difference begins where the network starts losing packets.

Ordinary protocols read a loss as a traffic jam and drop the speed. On a wire at home that is right. On mobile, on someone else’s Wi-Fi and on a crowded international link there is always loss — and the speed falls where the channel is in fact free.

Inside it is QUIC over UDP with its own speed control — Brutal. You tell it the width of the channel and it holds it, instead of guessing from losses.

On a line with a couple of percent of loss that is the whole difference: an ordinary tunnel sags several times over, this one carries on.

The price is honest: declare more width than you have and the excess simply drowns. So the number is set by the real channel.

In an ordinary tunnel all your connections travel inside one. A packet goes missing and the whole pipe waits: tabs, downloads and the call alike.

QUIC carries streams apart. A loss in one does not touch the others — video does not freeze because a picture is loading next to it.

• OpenVPN — old and slow, and in TCP mode it is a tunnel inside a tunnel: under loss it seizes up.
• WireGuard — fast and elegant, but recognised from the first packet. Where it is looked for, it does not survive.
• Shadowsocks and VLESS — they hide well, but they ride on TCP with all its habits under loss.

Hysteria2 takes both: speed on a bad line and staying unnoticed.

The server listens on 443 and speaks TLS 1.3 with a real certificate. To anyone arriving without a key it answers like an ordinary site: you can put a live page there, and the curious will see exactly that.

The traffic itself looks like HTTP/3, of which there is plenty on the network today. If the network is picky about QUIC, obfuscation goes on top.

UDP passes straight through instead of being wrapped in TCP. For games, voice and video calls that is the difference between playable and jumping ping.

On top of that the connection comes up in a single handshake: the client attaches noticeably faster than TCP with TLS over it.

It lives on UDP. There are networks where UDP is cut entirely — there no protocol of this family will save you, and we will not pretend otherwise.

And it does not fix your own network. If the network at home is bad, it will not get better.