I Built Free Malaysian Finance Calculators with Pure HTML/CSS/JS — No Framework, No Backend

A few months ago I set out to build a suite of financial calculators for the Malaysian market. Stamp duty, EPF contributions, zakat, rental yield, unit trust fees — the kind of tools that exist on clunky government portals or behind paywalls on financial sites. My constraint: no backend, no database, no build step. Just files I could push to GitHub Pages and have live in minutes. Here's what I learned. Why Vanilla JS? The first question developers ask is: why not React/Vue/Svelte? For calculator tools, a framework is pure overhead. Here's the math: A React app with a single calculator ships ~40-100KB of JS just for the runtime A vanilla JS calculator ships maybe 3-8KB total GitHub Pages serves static files globally via CDN with zero config For users on Malaysian mobile networks (where 4G coverage is patchy outside KL), this matters. PageSpeed scores matter for SEO. And frankly, a compound interest formula doesn't need reactive state management. The other reason: longevity. Framework ve