net package, you will see two classes related to URL encoding: java.net.URLEncoder - This class contains static methods for converting a String to the Otherwise, use application/x-www-form-urlencoded. The MIME types you mention are the two Content-Type headers for HTTP POST requests that user-agents (browsers) must support. Node.js POST does not work. Node.js server: get body from POST request. php - Handle application/x-www-form-urlencoded POST request using php. application/x-www-form-urlencoded. Thats the format browsers send when you submit a simple form on the web.It differs slightly from format to format. application/x-www-form- urlencoded.