What is "406-Not Acceptable Response" in HTTP?

In my Ruby on Rails application I tried to upload an image through the POSTMAN REST client in Base64 format. When I POST the image I am getting a 406 Not Acceptable Response. When I checked my database, the image was there and was successfully saved.

What is the reason for this error, is there anything I need to specify in my header?

My request:

URL --- http://localhost:3000/exercises.json

Header:

Content-Type  -  application/json

Raw data:

{
    "exercise": {
        "subbodypart_ids": [
            "1",
            "2"
        ],
        "name": "Exercise14"
    },
    "image_file_name": "Pressurebar Above.jpg",
    "image":"******base64 Format*******"
}

Your operation did not fail.

Your backend service is saying that the response type it is returning is not provided in the Accept HTTP header in your Client request.

Ref: http://en.wikipedia.org/wiki/List_of_HTTP_header_fields

1. Find out the response (content type) returned by Service.
2. Provide this (content type) in your request Accept header.

http://en.wikipedia.org/wiki/HTTP_status_code -> 406

> 406 Not Acceptable > The resource identified by the request is only capable of generating response entities which have content characteristics not > acceptable according to the accept headers sent in the request.

406 happens when the server cannot respond with the accept-header specified in the request. In your case it seems application/json for the response may not be acceptable to the server.

You mentioned you're using Ruby on Rails as a backend. You didn't post the code for the relevant method, but my guess is that it looks something like this:

def create
  post = Post.create params[:post]
  respond_to do |format|
    format.json { render :json => post }
  end
end

Change it to:

def create
  post = Post.create params[:post])
  render :json => post
end

And it will solve your problem. It worked for me :)

"Sometimes" this can mean that the server had an internal error, and wanted to respond with an error message (ex: 500 with JSON payload) but since the request headers didn't say it accepted JSON, it returns a 406 instead. Go figure. (in this case: spring boot webapp).

In which case, your operation did fail. But the failure message was obscured by another.

You can also receive a 406 response when invalid cookies are stored or referenced in the browser - for example, when running a Rails server in Dev mode locally.

If you happened to run two different projects on the same port, the browser might reference a cookie from a different localhost session.

This has happened to me...tripped me up for a minute. Looking in browser > Developer Mode > Network showed it.

const request = require('request');

const headers = {
    'Accept': '*/*',
    'User-Agent': 'request',
};

const options = {
    url: "https://example.com/users/6",
    headers:  headers
};

request.get(options, (error, response, body) => {
    console.log(response.body);
});

In my case, I added:

Content-Type: application/x-www-form-urlencoded

solved my problem completely.

If you are using 'request.js' you might use the following:

var options = {
  url: 'localhost',
  method: 'GET',
  headers:{
    Accept: '*/*'
  }
}

request(options, function (error, response, body) {
  ...
})

In my case for a API in .NET-Core, the api is set to work with XML (by default is set to response with JSON), so I add this annotation in my Controller :

[Produces("application/xml")]
public class MyController : ControllerBase {...}

Thank you for putting me on the path !