Everything Prettier's Babel parser accepts: ES2024, JSX, optional chaining, top-level await, decorators, class fields and private methods. TypeScript-specific syntax such as type annotations and interfaces is not — that needs the TypeScript parser.
Is this the same as Prettier in my editor?
Yes, it is Prettier's standalone build running in your browser, so the output matches your editor for the same options. The one difference is that this page cannot read your project's .prettierrc, so set the options above to match it.
Can it recover minified code?
It can re-indent minified JavaScript and make it readable, but it cannot restore what the minifier deleted. Variable names mangled to a, b, c stay mangled, and dead code that was eliminated is gone. For that you need a source map.