History
Hysteria was born thanks to a Chinese audience that despaired of breaking through the Great Firewall with conventional methods. The developers thought: "Why does everyone use TCP? Let's try QUIC." QUIC is the protocol that modern HTTP/3 (the fastest web) runs on. Version 1 came out in 2022, and Hysteria 2 became a real hit in 2025-2026.
Advantages
The killer feature of Hysteria 2 is its congestion control algorithm called Brutal. Conventional protocols panic and slow down when packets are lost. Brutal does the opposite: it starts sending even more packets to break through the wall.
Plus it disguises itself excellently. In "Masquerade" mode your server looks like an ordinary HTTP/3 website. If a censor knocks on it, they get a 404 page or a redirect to Bing.
Disadvantages
Hysteria 2 runs over UDP. And UDP in some networks (for example, Russian mobile carriers) is either heavily rate-limited or simply dropped. Also, Brutal is a double-edged sword. With wrong settings it can take down your own server.
Summary
Hysteria 2 is ideal for watching video and heavy content on unstable networks. It's aggressive, fast, and can impersonate a web server.