HTTP POST Form Data Visualization Tool

What This Tool Does

This tool demonstrates how HTML forms can be submitted via POST in two different formats:

• application/x-www-form-urlencoded — A standard encoding where form fields are URL-encoded and concatenated in the body (e.g., field1=value1&field2=value2). This is typically used for simple form submissions without files.
• multipart/form-data — An encoding that splits form fields (including file uploads) into separate parts, each preceded by a boundary marker. This is required when uploading files.

By selecting one of these modes from the dropdown, the tool sets the corresponding Content-Type for the form. After you fill out the form and click "Submit Data," the tool will display:

• The exact Content-Type header that would be sent
• A visual representation of the form's body content
• For binary files, metadata will be shown instead of raw binary content

Note: For demonstration purposes, the form submission is intercepted by JavaScript (event.preventDefault()), so the data is never actually sent to a server.