UPDATE

Request Streaming will be part of .NET 9: dotnet/runtime#91295, dotnet/runtime#91699

dotnet WASM BrowserHttpHandler with support for ReadableStream request bodies

This allows the usage of request streaming when supported. In addition to that it also needs to be opted in via:

request.Options.Set(BrowserHttpHandler.EnableStreamingRequest, true);

For streaming requests over HTTP 1 the following setting is also required:

request.SetBrowserRequestOption("allowHTTP1ForStreamingUpload", true);

Currently this feature Experimental Web Platform features needs to be enabled in chrome://flags/

Code

• Index.razor: streaming inputs

• Upload.razor: upload multipart form file

• BrowserHttpHandler.cs: modified version of the dotnet/runtime code

Resources

• dotnet runtime issue: dotnet/runtime#36634
• Google Chrome feature status: https://www.chromestatus.com/feature/5274139738767360
• ReadableStream MDN: https://developer.mozilla.org/docs/Web/API/ReadableStream/ReadableStream
• web.dev article which the index example is based on: https://web.dev/fetch-upload-streaming/