While WebAssembly is better for some things than JS, for most code you run in a browser, it's no improvement and actually worse. When you do need wasm, though,

While WebAssembly is better for some things than JS, for most code you run in a browser, it's no improvement and actually worse. When you do need wasm, though, then it opens up entire new possibilities, things you really couldn't do before. I like to compare wasm to the video element: not every site should use it, and it won't replace JS or CSS or HTML, but its existence makes things like YouTube and Netflix possible. The future of code on the web is JS + wasm.