When comparing FAST vs Lara, the Slant community recommends FAST for most people. In the question“What are the best web component libraries/frameworks?” FAST is ranked 3rd while Lara is ranked 9th. The most important reason people chose FAST is:
FAST is super performant, with a small package and memory footprint.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Performance
FAST is super performant, with a small package and memory footprint.
Pro Web Components
Use industry standard components in multiple frontend frameworks.
Pro Composable
FAST components are super composable making it easy to build other, more complex components.
Pro Get only what you need
FAST extensively uses tree shaking so you only get the features you need, reducing project bloat.
Pro Built on TypeScript
FAST is built using TypeScript.
Pro FAST-Element
FAST components are built on fast-element which can be used on its own to quickly build new Web Components.
Pro Custom tooling libraries
Create your own component portals or other tools using FAST tooling libraries.
Pro Adaptive UI
Easily customize the style/theme using flexible properties.
Pro Cross-Platform
Can develop in Windows, Linux and MacOS.
Pro Server-side rendering engine
Lara has a server-side rendering engine with virtual DOM.
Pro Open Source
Apache 2.0 license.
Cons
Con No IE 11 Support
FAST uses Web Components so won't work on IE 11.