[masklinn]

> Is chunked transfer encoding no longer a thing in HTTP/3? It used to be a valid reason to omit Content-Length.

IIRC HTTP/2 and HTTP/3 are essentially always chunked. I would expect a missing content-length to be completely valid.

[Matthias247]

That is correct. By default HTTP/2 and HTTP/3 requests are streamed and can have an "infinite" length. The presence of a content-length header will limit limit that length, and inform the peer upfront on how much data will be sent.

For HTTP/1.1, a stream where the length is not known upfront required the usage of chunked encoding. With HTTP/2 and /3 that encoding is no longer required since the underlying protocol already support framing and contains and end-of-stream information.