Promises are a way to deal with async code. Parsing JSON is synchronous and CPU-bound, so promises offer no benefit. And since web pages are single-threaded[0],

Promises are a way to deal with async code. Parsing JSON is synchronous and CPU-bound, so promises offer no benefit. And since web pages are single-threaded[0], there isn't really any way you can parse JSON in the background and wait on the result. [0]: There is now the Web Workers API which does allow you to run code in the background. I've never used it, but I have heard that it has a pretty high overhead since you have to communicate with it through message passing, so it's possible you wouldn't actually gain anything by using it to parse a large JSON object. https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers...