Increase upload request length limit in Kestrel

Question

I am running an ASP.NET Core web app and want to upload large files.

I know that when running IIS, the limits can be changed via web.config:

<httpRuntime maxRequestLength="1048576" /> 
...
<requestLimits maxAllowedContentLength="1073741824" /> 

How can you do the equivalent while running the new ASP.NET Core Kestrel web server?

I get the exception "Request body too large."

Answer 1

I found this helpful announcement that confirms there is a 28.6 MB body size limit starting with ASP.NET Core 2.0, but more importantly shows how to get around it!

To summarize:

For a single controller or action, use the [DisableRequestSizeLimit] attribute to have no limit, or the [RequestSizeLimit(100_000_000)] to specify a custom limit.

To change it globally, inside of the BuildWebHost() method, inside the Program.cs file, add the .UseKestrel option below:

WebHost.CreateDefaultBuilder(args)
  .UseStartup<Startup>()
  .UseKestrel(options =>
  {
    options.Limits.MaxRequestBodySize = null;
  }

For additional clarity, you can also refer to the Kestrel options documentation.

Answer 2

The other answer is for ASP.NET Core 2.0, but I would like to provide the solution for .NET Core 3.x web API.

Your code in program.cs must be like this to work:

public class Program
{
    public static void Main(string[] args)
    {
        CreateHostBuilder(args).Build().Run();
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
                webBuilder.UseKestrel(options =>
                {
                    options.Limits.MaxRequestBodySize = null;
                });
            });
}