Warning: Missing boundary in multipart/form-data POST data in Unknown on line 0

Question

I am working on file uploader which upload the image when the input is changed my code for the form in html is

Answer 1

Instead of sending the data as multipart/form-data:

ajax.setRequestHeader("Content-Type", "multipart/form-data");

You should send it as application/json:

ajax.setRequestHeader("Content-Type", "application/json");

Answer 2

You have to just remove the following line:

ajax.setRequestHeader("Content-Type", "multipart/form-data");