What is HTTP/3: A Deeper Dive

HTTP/3 is not just another update; it's a substantial leap forward in web technology. As of June 2022, it's officially a Proposed Standard in RFC 9114. If you’re in the web game, like us at Uploadcare, you should be on this.

The DNA of HTTP/3

HTTP/3 is pretty much the same as its ancestors in the semantics—think status codes and request methods. But it's like they've been through a makeover for the modern web. It's HTTP but with less latency and more speed. Real-world usage shows it can be over 3x faster than HTTP/1.

User Adoption with The Numbers

As of now, 94% of tracked browsers support HTTP/3, and it's being used on 26% of the top 10 million websites. This includes major players like Google Chrome, Microsoft Edge, and Firefox. Safari's playing hard to get; it’s there but disabled by default.

History Lesson

HTTP/3 has roots in a draft by the QUIC working group. It was initially a sequel to HTTP/2 but quickly earned its unique identity and name. The name change was proposed by Mark Nottingham, Chair of the IETF HTTP and QUIC Working Groups, to highlight its uniqueness.

QUIC: The Transport Layer Hero

HTTP/3 uses QUIC, a protocol designed to fix the "head-of-line blocking" issue—a packet loss problem that plagued HTTP/2. QUIC is like that friend who ensures you get to the party on time, no matter how chaotic the traffic.

DNS Magic: SVCB and HTTPS Records

HTTP/3 introduces new DNS resource records, SVCB and HTTPS, allowing quicker connections without the usual handshaking dance. It's like skipping the line at a club because you know the bouncer.

Browser Support and Libraries

  • Chrome: Enabled by default since April 2020.
  • Firefox: Enabled by default since April 2021.
  • Safari: Enabled but disabled by default as of Safari 16.
  • Libraries: Numerous open-source libraries, like lsquic and nghttp3, support HTTP/3.

Server-Side Adoption

LiteSpeed Web Server was the first to enable HTTP/3 by default in June 2021. Nginx jumped on the bandwagon in May 2023. Even Microsoft IIS has native support in Windows Server 2022/Windows 11.

HTTP/3 and Uploadcare

For us at Uploadcare, HTTP/3's low latency and high speed are tempting. But we're also looking at server-side implementations and CPU usage. HTTP/3 is the future of the internet, and we are closely monitoring its development and planning to support it in the future.


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