Process multiple files with forms: a tutorial on binary data and loops

Let a user load multiple files with a Form node, and process the binary data. A very important workflow for many tools.

This is a learning example of several core concepts that are hard to grasp in n8n: - $binary data - Loop and $runIndex - Split Out

The Save File deomonstrates how to access the binary data correctly, but could be swapped to POST the files to an AI, for example.