What it improves

Built on QUIC over UDP, it removes head-of-line blocking at the transport layer and recovers faster from packet loss — which is where mobile networks spend much of their time.

Who notices

Users on congested mobile connections see the largest improvement. On a good fixed line the difference is often marginal.

How to enable it

Usually a server or CDN toggle rather than an application change. Clients that cannot negotiate it fall back to HTTP/2 automatically.