enctype

Enctype is an attribute of the HTML form element that specifies how the submitted form data should be encoded when it is sent to the server. The encoding type primarily affects POST submissions, while for GET submissions the data are included in the URL query string and the enctype attribute is generally ignored.

The most common values are: application/x-www-form-urlencoded, which is the default. In this mode, form fields are encoded as key=value pairs separated by ampersands, with certain characters escaped. multipart/form-data, which is required for forms that include file uploads; the data are sent in separate parts, allowing binary data to be transmitted safely. text/plain, which sends plain text without key=value encoding; this value is rarely used in practice and is not widely supported by servers. A form may specify only one of these values through the enctype attribute, and some servers or frameworks expect multipart/form-data for file inputs.

Usage guidelines: use application/x-www-form-urlencoded for standard forms without files, as it yields compact data and broad compatibility. Use multipart/form-data when the form includes input type="file", or when binary data must be transmitted. The text/plain option is largely obsolete for modern web applications. The enctype attribute is defined on the form element, and it works in conjunction with the method attribute (most commonly method="post"). If the server expects a specific encoding, the form’s enctype should be set accordingly, and server-side code must parse the incoming data in the chosen format.

Example: <form action="/upload" method="post" enctype="multipart/form-data">.