Trouble understanding what GatsbyJS can do

Hey y’all!

I’m investigating GatsbyJS and I’m having a little bit of a hard time understanding a couple of things.

1: Does GatsbyJS always produce a site that uses the React framework? (I know it uses React in the process of building the site). I’m just talking about the resulting static files that Gatsby produces.

2: Is it possible for GatsbyJS to produce a site that does not have any JS? A simple one page site without interactivity would not need JS for example. Is it possible to create such a one-page-website with GatsbyJS?

3: I ran the example code from here ( and did gatsby build . That hello world example ends up being 704KB (!) of code, just for a “hello world”. A lot of it is source maps, that the browser only requests when debugging (right). But there’s still quite a lot in that page. What is all that stuff?