Comparing HTTP/3 vs. HTTP/2 Performance

Cloudflare has announced support for HTTP/3, the successor to HTTP/2, during its birthday week last year. Over 113,000 zones have activated HTTP/3 and can be accessed using experimental browsers. The company launched support in partnership with Google, who also added experimental support in Chrome. Firefox, Opera, Microsoft Edge, and Safari have since followed suit. HTTP/3 is expected to offer increased performance, specifically around fetching multiple objects simultaneously. It also offers 0-RTT support, which means subsequent connections can start up much faster by eliminating the TLS acknowledgement from the server when setting up the connection. Real-world tests have shown that HTTP/3 performs better than HTTP/2 in some cases and at worst similar to it. As the standard finalizes, Cloudflare is looking forward to seeing browsers add support for HTTP/3 in mainstream versions. The company continues to support the latest drafts while exploring more ways to leverage HTTP/3 to improve performance.