Hysteria2 or VLESS + Reality: what differs and which to pick
Both protocols get around blocking, and they are built on opposite principles. Hysteria2 runs over UDP and wins on unstable networks. VLESS + Reality disguises itself as ordinary HTTPS and passes where UDP is dropped outright. Here is when to use which.
What Hysteria2 is
Hysteria2 is a protocol built on QUIC, the transport Google designed for HTTP/3. QUIC runs over UDP and does something TCP cannot: it recovers a lost packet without stalling the whole stream. In TCP a single lost packet holds up everything queued behind it — head-of-line blocking. On a wired connection the difference is invisible, but on a mobile network, where 2-5% loss is ordinary, it decides everything. Hysteria2 also masquerades as an ordinary HTTP/3 site: point a browser at the server and you get a normal web page rather than any sign of a VPN.
What VLESS + Reality is
Reality is not a protocol of its own but a way of disguising VLESS. An ordinary TLS-based VPN gives itself away through its certificate: either self-signed or issued for a suspicious domain. Reality solves that outright — it presents the certificate of a real third-party site, www.bing.com for instance. From outside, the connection looks like an ordinary visit to that site: same certificate, same name in the TLS handshake. Telling them apart takes active probing, and even then the server answers as the real bing.com to anyone who does not hold the key.
Packet loss: where Hysteria2 wins
Mobile networks lose packets constantly — handing over between towers, weak signal, a congested cell. Over TCP that shows up as speed collapsing in waves, because the connection keeps waiting on retransmission. QUIC in Hysteria2 handles each stream independently, so a loss in one does not hold up the rest. In practice the difference shows wherever loss exceeds 1-2%: on the underground, on a train, on crowded Wi-Fi. That is why Hysteria2 is first in our server list.
Blocking: where Reality wins
Hysteria2 has one weak point — it runs over UDP, and UDP is often dropped wholesale. Corporate networks, hotel Wi-Fi and a few carriers pass only TCP on ports 80 and 443. There Hysteria2 cannot come up at all, however it is configured. Reality rides TCP on 443 and looks like ordinary HTTPS, so it gets through those filters. The other side of that: TCP connections are easier to analyse, and deep packet inspection eventually learns to recognise even Reality. We have watched sessions die a few minutes in.
What to pick in practice
Start with Hysteria2 — in the server list it is the plain entry with no marking. On most networks it is faster and steadier. If the connection will not establish, or drops immediately, switch to the entry for the same country marked TCP, which is Reality. Nothing needs configuring: both servers are already in the subscription and the app remembers your choice. If neither works, the problem is usually the network rather than the protocol — try mobile data instead of Wi-Fi.