ASP NET Core form POST results in a HTTP 415 Unsupported Media Type response

Question

Sending a form POST HTTP request  Content-Type  application x-www-form-urlencoded  to the below controller results into a HTTP 415 Unsupported Media Type response   public class MyController   Controller        HttpPost      public async Task lt IActionResult gt  Submit  FromBody  MyModel model                                Form post HTTP headers   POST  submit HTTP 1 1 Host  example com 1337 Connection  keep-alive Content-Length  219 Pragma  no-cache Cache-Control  no-cache Origin  https   example com 1337 Upgrade-Insecure-Requests  1 User-Agent  Mozilla 5 0  Windows NT 10 0  Win64  x64  AppleWebKit 537 36  KHTML  like Gecko  Chrome 58 0 3029 110 Safari 537 36 Content-Type  application x-www-form-urlencoded Accept  text html application xhtml xml application xml q 0 9 image webp     q 0 8 Referer  https   example com 1337 submit Accept-Encoding  gzip  deflate  br Accept-Language  en-US en q 0 8 nl q 0 6   This used to work with ASP NET MVC 5 on  NET 4 6

User · Answer

Follow the below steps   Add to sending request header Content-Type field   axios post   Order    orderId          headers    Content-Type    application json         Every data  simple or complex type  sent with axios should be placed without any extra brackets  axios post   Order    orderId           WARNING  There is one exception for string type - stringify it before send  axios post   Order    JSON stringify address           Add method to controller   HttpPost  public async Task lt IActionResult gt  Post  FromBody int orderId        return Ok

User · Answer

This is my case  it s run Environment  AspNet Core 2 1 Controller   public class MyController                    HttpPost      public ViewResult Search  FromForm MySearchModel searchModel                               return View  Index   viewmodel             View    lt form method  post  asp-controller  MyController  asp-action  Search  gt       lt input name  MySearchModelProperty  id  MySearchModelProperty    gt       lt input type  submit  value  Search    gt   lt  form gt

User · Answer

For forms  use the  FromForm  attribute instead of the  FromBody  attribute   The below controller works with ASP NET Core 1 1   public class MyController   Controller        HttpPost      public async Task lt IActionResult gt  Submit  FromForm  MyModel model                                Note   FromXxx  is required if your controller is annotated with  ApiController   For normal view controllers it can be omitted

User · Answer

the problem can because of MVC MW you must set formatterType in MVC options   services AddMvc options   gt                                options UseCustomStringModelBinder                    options AllowEmptyInputInBodyModelBinding   true                  foreach  var formatter in options InputFormatters                                        if  formatter GetType      typeof SystemTextJsonInputFormatter                             SystemTextJsonInputFormatter formatter  SupportedMediaTypes Add                              Microsoft Net Http Headers MediaTypeHeaderValue Parse  text plain                                      AddJsonOptions options   gt                                options JsonSerializerOptions PropertyNameCaseInsensitive   true

User · Answer

In my case 415 Unsupported Media Types was received since I used new FormData   and sent it with axios post      but did not set headers   content-type   multipart form-data    I also had to do the same on the server side   Consumes  quot multipart form-data quot    public async Task lt IActionResult gt  FileUpload  FromForm  IFormFile formFile

User · Answer

As addition of good answers  You don t have to use  FromForm  to get form data in controller  Framework automatically convert form data to model as you wish  You can implement like following    HttpPost  public async Task lt IActionResult gt  Submit MyModel model

User · Answer

First you need to specify in the Headers the Content-Type  for example  it can be application json   If you set application json content type  then you need to send a json   So in the body of your request you will send not form-data  not x-www-for-urlencoded but a raw json  for example   Username    user    Password    pass    You can adapt the example to various content types  including what you want to send   You can use a tool like Postman or curl to play with this

User · Answer

HTTP 415 Unsupported Media Type response  stems from Content-Type in header of your request  for example in javascript by axios    Axios               method   post               headers     Content-Type    application json                url                   data  data      an object u want to send              then function  response                console log response

User · Answer

Another trap of note is making sure you re not decorating controllers with the Consume Attribute as below   Produces  quot application json quot     Consumes  quot application json quot    public class MyController   Controller  This will fail with a 415 Unsupported Media Type if the upload is NOT JSON  A  quot friend of mine quot  was recently caught out by this like so  public class MyFileUploadController   MyCustomController        Produces  quot application json quot     Consumes  quot application json quot    public class MyCustomController   ControllerBase

User · Answer

You can use  FromBody  but you need to set the Content-Type header of your request to application json  i e   Content-Type  application json

User · Answer

In my case  I received the HTTP 415 Unsupported Media Type response  since I specified the content type to be TEXT and NOT JSON  so simply changing the type solved the issue  Please check the solution in more detail in the following blog post  https   www howtodevelop net article 20 unsupported-media-type-415-in-aspnet-core-web-api

[c#] ASP.NET Core form POST results in a HTTP 415 Unsupported Media Type response

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