Tool for sending multipart/form-data request
UPDATE: I have created a video on sending multipart/form-data requests to explain this better.
Actually, Postman can do this. Here is a screenshot
Newer version : Screenshot captured from postman chrome extension
Another version
Older version
Make sure you check the comment from @maxkoryukov
Be careful with explicit Content-Type header. Better - do not set it's value, the Postman is smart enough to fill this header for you. BUT, if you want to set the Content-Type: multipart/form-data - do not forget about boundary field.
The usual error is one tries to put Content-Type: {multipart/form-data}
into the header of the post request. That will fail, it is best to let Postman do it for you. For example:
Suggestion To Load Via Postman
Fails If In Header
Works