[thinkloop]

A hello world react app with everything you would typically need (redux, router, etc.) starts at 100K+. Svelte is a couple K.

A react app has massive abstraction to render on every frame, Svelte compiles out the framework to render instant straight vanilla js (wins all perf tests).

Pre-compiling allows for beautiful syntax and more flexible app structure, since you aren't limited to the runtime.

SSR and code-splitting are significantly easier and more straightforward.

React is designed for a billion-user site and it shows.

There really is zero cost to pre-compiling except mind-share, and only benefits. Of course an F100 company has many concerns above tech awesomeness, so no judgement on your selection criteria. But I assure you this movement is coming, react/vue/angular will adapt/change and/or people will move to Svelte-like solutions.

You can already see it happening in the article facebook released today [1]:

"By using rems, we can respect user-specified defaults and are able to provide controls for customizing font size without requiring changes to the stylesheet. Designs, however, are usually created using CSS pixel values. Manually converting to rems adds engineering overhead and the potential for bugs, so we have our build tool do this conversion for us."

[1] https://news.ycombinator.com/item?id=23116300

[nicoburns]

I'm not convinced that the 100kb is what's causing the perf problems though. It's not that hard to make a React app that loads almost instantly. There are lots of huge, slow react apps, but that's due to poor engineering choices not the framework.

[dwoot]

You have not looked at Svelte. You've still the overhead of a virtual DOM and its diffing. People that turn a blind eye to Svelte will be blind-sided. It's like writing vanilla JS without all the baggage, because it's a compiler (think C++ versus Python).

I highly doubt that one can build a ReactJS app that loads faster than a Svelte one. I encourage you to try and share it. This is coming from someone that is a backend engineer that doesn't really do JS, but have had to for my own personal project and both perf and the subjective bit of expressiveness and joy of writing are important. Contrary to popular belief, people think that Svelte is trading perf for ugliness and lack of expressiveness.

[nicoburns]

So I had (an admittedly brief) look into Svelte on the back of your comment. And one thing that stands out to me is that it appears to be using string templating. This isn't a complete dealbreaker, but it's definitely a step back from the React world where everything is JavaScript. This was by far the biggest pain point in other frameworks like Angular, so I'd be pretty reluctant to go back to it.

Looking at the framework benchmarks (https://krausest.github.io/js-framework-benchmark/current.ht...), svelte is indeed a good bit faster than React. However, Inferno which takes a react-like virtual DOM approach but better optimised is faster still. So I'd be more inclined to go with that if I were willing to give up the React library ecosystem.

[uhoh-itsmaciek]

I see TypeScript support is on the road map. I haven't used it yet, but that's exciting.

[postalrat]

I love react. But when I hear developers say their react app loads instantly I think:

1) Their app is pretty small

2) Their machine is really fast