XLSForm is an open standard that lets you design complex surveys using nothing more than a spreadsheet. Instead of learning a proprietary form-builder interface, you work in Microsoft Excel or Google Sheets — tools you likely already know — and the resulting file is converted into a fully functional digital form that runs on mobile devices and web browsers. Because your survey lives in a plain .xlsx file, you can email it, track changes over time, and share it with colleagues who have no special software installed. The format has 3 core sheets – we will go over them one by one.