> For the complete documentation index, see [llms.txt](https://http3-explained.haxx.se/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://http3-explained.haxx.se/en/h3/h3-prio.md).

# Prioritization

The base HTTP/3 specification doesn't define prioritization itself. The HTTP/2 approach to prioritization has been deemed too complicated and is deprecated by the latest revision of the HTTP/2 specification [RFC 9113](https://www.rfc-editor.org/rfc/rfc9113.html). A simpler alternative, the Extensible Prioritization Scheme for HTTP ([RFC 9218](https://www.rfc-editor.org/rfc/rfc9218.html)), has been published separately, which can be used in both HTTP/2 and HTTP/3.

In HTTP/3, priority signals are sent in the form of the Priority header field and/or the PRIORITY\_UPDATE frame sent on the HTTP/3 Control Stream. Servers can act on these signals to schedule sending of HTTP response content. [RFC 9218](https://www.rfc-editor.org/rfc/rfc9218.html) provides scheduling guidance that is intended to improve client web application performance.