aidenybai/million

Million.js is an optimizing compiler (a tool that automatically rewrites your code to make it run faster) that works alongside React, a popular JavaScript library for building web interfaces. It is written in TypeScript and available as an open-source package. The problem it solves is a performance bottleneck built into how React works. Every time something on a page changes, like a counter going up, React has to compare the old version of the page to the new version and figure out what actually changed. This comparison process, called reconciliation or "diffing," gets slower as your page grows because React checks every element, even the ones that did not change. Million.js works by stepping in before React does this comparison. Instead of comparing everything, it already knows exactly which part of the page will change, so it skips the diff and updates the affected part of the page directly. The README describes this as changing reconciliation from linear time (slower as the page grows) to constant time (always fast, regardless of page size). You use Million.js by running a single command that automatically installs it and adjusts your project's configuration. No major code rewrite is needed, it plugs in to your existing React project and works behind the scenes as a compiler step. This is useful when you have a React app that feels sluggish during updates, especially pages with many interactive elements. The README claims components can run up to 70% faster after adding Million.js.