HTTP 3 is here
The demand for low latency web and mobile applications has brought significant evolution in HTTP protocol in recent years. While HTTP/1 has been in use since first published in 1997, HTTP/2 came as a major performance improvement in 2015. The use of multiplex connections, compressed headers and server-side push made HTTP/2 a lot faster than its predecessor.
Though HTTP/2 was a big step forward, it didn't solve all the problems which are inherent in its lower networking layer - TCP. The HPACK header compression mechanism used in HTTP/2 requires messages to be delivered in sequence. So if a TCP packet is lost, all HTTP/2 streams get blocked. Also, TCP has a slow start, and it increases the transmission rate gradually until it reaches the connection's optimum capacity.
To solve the above problems, Google created a new protocol called QUIC and has been using it with success. Now QUIC is making its way to HTTP protocol as the new proposed HTTP/3.
QUIC uses streams over UDP (not TCP). The QUIC streams share the same connection, so no additional handshakes and slow starts are required to create new ones. The QPACK header compression mechanism allows independent delivery of the streams. This fast connection setup and the ability to send packets over parallel streams makes HTTP/3 the future choice for the web.
To read more about HTTP/3 over QUIC, follow this link.