React 16 roughly three times faster than React 15, it includes few long-standing requested features:
- fragments: return an array of elements from a component’s render method.
- error boundaries: better error handling.
- portals: a first-class way to render children into a DOM node that exists outside the DOM hierarchy of the parent component
- support for custom DOM attributes: instead of ignoring unrecognized HTML and SVG attributes, React will now pass them through to the DOM.
- improved server-side rendering: supports streaming, so you can start sending bytes to the client faster; a new packaging strategy that compiles away process.env checks.
- reduced file size: React now uses Rollup to create flat bundles for each of its different target formats, resulting in both size and runtime performance wins.