When making large HttpPost requests, such as uploading files or loading documents into the Document Viewer, the maximum request size is limited by default. Several settings are required in ASP.NET Core and ASP.NET applications to prepare applications to handle larger requests.

There are also differences in the hosting server depending on whether you are using .NET Kestrel or IIS. This article will cover the necessary settings for both hosting servers.

ASP.NET Core

ASP.NET Core applications have a default limit of 30MB for the maximum request size. This limit is set in the Program.cs file in the ConfigureServices method. The ConfigureServices method is where you can configure services that the application will use. The ConfigureServices method is called before the Configure method, which is where the application's request pipeline is configured.

Kestrel

To increase the maximum request size, you can use the Configure<KestrelServerOptions> method to configure the Kestrel server options. The Configure<KestrelServerOptions> method is called on the IServiceCollection interface, which is the collection of services that the application will use.

Here is an example of how to increase the maximum request size to approximately 8.59 GB:

builder.Services.Configure<KestrelServerOptions>(options =>
{
    options.Limits.MaxRequestBodySize = int.MaxValue; 
});

IIS

If you are hosting an ASP.NET Core application in IIS, you must configure the maximum request size in web.config. The web.config file is an XML file containing application configuration settings. The web.config file is located in the application's root directory.

Here is an example of how to increase the maximum request size to the maximum value:

<system.webServer>
  <security>
    <requestFiltering>
      <requestLimits maxAllowedContentLength="4294967295" />
    </requestFiltering>
  </security>
</system.webServer>

ASP.NET

The maximum request size for ASP.NET applications is limited to 4 MB by default. This limit is set by your web.config file.

IIS Request Filtering

At the IIS level, the Request Filtering module is used to limit the size of data that IIS accepts. Increase the maxAllowedContentLength value, which specifies the size of the POST buffer in bytes.

The default is 30000000 bytes (28.6 MB). The maximum value is 4294967295 bytes (4 GB).

Here is an example of how to increase the maximum request size:

<system.webServer>
  <security>
    <requestFiltering>
      <requestLimits maxAllowedContentLength="4294967295" />
    </requestFiltering>
  </security>
</system.webServer>

HttpRuntime maxRequestLength

ASP.NET has its own setting for limiting the size of uploads and requests. Use the maxRequestLength property of the httpRuntime element.

The default size is 4096 kilobytes (4MB). The maximum value is 2,147,483,647 kilobytes (~82 terabytes). The following setting defines a maximum size of 500 megabytes.

The length of the request can be defined as follows:

<system.web>
  <httpRuntime targetFramework="4.8" maxRequestLength="1048576" executionTimeout="120" />
</system.web>

These settings will allow you to handle larger requests in your ASP.NET Core and ASP.NET applications.

Conclusion

When making large HttpPost requests, such as uploading files or loading documents into the Document Viewer, the maximum request size is limited by default. Several settings are required in ASP.NET Core and ASP.NET applications to prepare applications to handle larger requests.