When you need to build small custom web components that can be used across all frameworks - Angular, React, Vue vanilla JS and others - Stencil is an ideal tool. Stencil enables you to create platform-independent components that can be exported as a true web component and used anywhere.

Stencil is basically a compiler, not necessarily a UI library. A compiler that transforms TSX (TypeScript + JSX) into self-contained custom components.
Before you start learning about the tool, it’s important to note that Stencil is not another heavy JavaScript framework you need to learn. If you have worked with Angular or React, or understand web components, then Stencil is worth a look.