Is it possible to increase the max URI lenght in HttpClient? (Invalid URI: The uri string is too long)

Question

I am using an HttpClient in Dotnet 5 and try to create a query with a very long URI. I get this exception

Invalid URI: The uri string is too long

I tried to figure out where it comes from and it seems it boils down to this line with a constant:

internal const int c_MaxUriBufferSize = 0xFFF0;

It seems that it is actually impossible to have a URL longer than 64K, but there is perhaps something I did not figure out?

Does this answer your question? [HttpClient: The uri string is too long](https://stackoverflow.com/questions/38440631/httpclient-the-uri-string-is-too-long) — Peter Csala, Jan 19 '21 at 07:24
@PeterCsala Hi, no, that answers a completely different question ironically — Ilya Chernomordik, Jan 19 '21 at 08:01

score 1 · Answer 1 · answered Jan 19 '21 at 07:47

In short: you can't.

If you look at the source of Uri then it becomes clear why.

Inside its GetException method it translates ParsingError.SizeLimit into an UriFormatException.

So, if we look at the code of the Uri to see when it fails with ParsingError.SizeLimit then we will find these:

In the first two cases the limit is checked against c_MaxUriBufferSize (1), which is defined as this:

internal const int c_MaxUriBufferSize = 0xFFF0;

In later cases the limit is checked against ushort.MaxValue.

Unfortunately none of them are changeable.

thanks for the answer, that's the same I figured... – Ilya Chernomordik Jan 19 '21 at 08:01 — Ilya Chernomordik, Jan 19 '21 at 08:01

1 Answers1