Automating Web Table Exports with JavaScript: A Practical Guide

You've found a table on a website. You need that data in a spreadsheet. The obvious path—copy, paste, clean up in Excel—works once. But what if you need this data weekly? Or from 50 different pages? This guide shows you how to extract HTML tables programmatically with JavaScript, handle the edge cases that break naive approaches, and export to formats your tools actually accept. The Naive Approach (And Why It Fails) The simplest extraction looks like this: function extractTable ( table ) { return Array . from ( table . rows ). map ( row => Array . from ( row . cells ). map ( cell => cell . textContent . trim ()) ); } This works for simple tables. It breaks immediately when you hit: Rowspan/colspan — Cells that span multiple rows or columns Nested tables — Tables inside table cells Hidden content — <style> , <script> , or display:none elements Special characters — Newlines, tabs, and quotes in cell content Let's fix each one. Handling Rowspan and Colspan When a cell has rowspan="2" , it