Free HTML Form to Google Sheets with doPost – Apps Script

The doPost method, explained properly. This is the Apps Script function that receives a POST request from outside Google, and once you understand it, any form on any website can write into a Google Sheet.

What doPost actually is

Apps Script gives a web app two entry points: doGet for a page being opened, and doPost for data being sent to it. The walkthrough builds the handler step by step — reading the posted parameters, picking the sheet, appending the row, returning a response — so you can see where the data arrives and what to do with it, rather than copying a block that works for reasons you cannot explain.

The form side

The HTML form is built from scratch with HTML and CSS, and posted with plain JavaScript — no jQuery, no library, no framework. That is deliberate: a fetch to a URL is something you can drop into any page you already have, whatever it was built with.

Why it matters beyond forms

Once doPost is clear, the same endpoint takes data from anywhere that can make an HTTP request: a website form, a mobile app, an IoT device, Zapier, n8n, a PHP script. The sheet becomes a free endpoint for collecting anything, with no server behind it.

Which form project to pick

This one is the method — written for understanding doPost and posting with plain JavaScript. If you would rather have the ready-made receiver and a working form to adapt, the custom HTML form to Google Sheets project covers the same ground as a finished build.