WeVividWeVividFormat and beautify minified JavaScript.
Prettier's JavaScript parser (Babel), the same one used by many code editors, giving consistent formatting.
No — it strips comments and collapses whitespace for a quick size reduction, but doesn't rename variables or do the deep optimisation a real build-time minifier (like Terser) performs. Use a build tool for production bundles.
No — everything runs entirely in your browser.