5 ms·
Other way round. Neither blocks parsing/render during downloads, but async scripts execute immediately onLoad – blocking render. defer "defers" that until after
by lelandfe 4y ago
Other way round. Neither blocks parsing/render during downloads, but async scripts execute immediately onLoad – blocking render. defer "defers" that until after document parsing is finished. https://developer.mozilla.org/en-US/docs/Learn/JavaScript/First_steps/What_is_JavaScript#async_and_defer https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Fi...