HTTP/3 ( H3 ) is the 3rd and the latest revision of HTTP ( Hypertext Transfer Protocol ). HTTP/3 is based on Google’s “HTTP-over-QUIC”. Cloudflare and Chrome already supports HTTP/3, Firefox will follow this trend in late Q3 of 2019.
One of the core features of HTTP/3: instead of using TCP as the transport layer, HTTP/3 is using QUIC, which introduces streams as a ‘priority citizens’ at the transport layer. QUIC streams share the same QUIC connection – it means no extra handshakes and delayed starts are necessary to create the new ones. The packet loss of one stream is not affecting others – QUIC streams are delivered independently ( QUIC packets are implemented on top of UDP ).