When comparing Assemble vs Gatsby JS, the Slant community recommends Gatsby JS for most people. In the question“What are the best static site generators?” Gatsby JS is ranked 6th while Assemble is ranked 16th.
Ranked in these QuestionsQuestion Ranking
Pro Built on node.js
Pro Powered by a popular template engine Handlebars
Handlebars is the default template engine for Assemble, but you can add any template any you want.
Pro Highly customizable
Pro Markdown support
Pro Highly extensible
Assemble can be extended with plugins/middleware, helpers and mixins.
Pro Nested layout support
Assemble makes it easy to work with layouts. Layouts are used to "wrap" pages with common page elements, such as a header, footer etc. You can even nest layouts!
Pro Use mainstream build tools Grunt or Gulp
Pro No page reload when navigating
Pro Based on React.js
Editing markup is phenomenally easy when you have components.
Pro A lot of plugins
Gatsby offers a lot of plugins to integrate tools like SASS, typescript, styled components, etc.
Pro Live reload
Every change you make can be almost immediately seen in a browser.
Pro Open Source
Pro Take content from any source
Gatsby can generate the pages with content from any sources like Drupal, Wordpress, Contentful, etc. If the source plugin is not coded for your solution, you can create it.
Pro A static site and a React app in one
The static pages are generated by Server Site Rendering of the React app. So you have all benefits of a static site, and all benefits of a React app, which is very powerful.
Pro GraphQL Data Layer
Pro A lot of examples
Gatsby have a lot of examples sites in his github repository.
Pro Very active development
Gatsby is very actively developed and the maintainers are very helpful.
Pro Beautiful out-of-the-box blog starters
Pro Built-in code and data splitting
Con Documentation can be hard to navigate
Especially for someone new to Assemble, it can be difficult to find what you're looking for in the documentation.
Con A bit raw
You'll maybe have to tweak some JSX if you want something that's not covered by available themes.