6 replies

defer vs async keyword in script tags

Hello, quick question, I know that both

defer

defer

and

async

async

will load our external javascript file at the same time as our HTML parser is working. The difference is that

defer

defer

will only be "triggered" after the HTML parser has been completed.

On the other hand, the

async

async

keyword would mean that "run the external file whether or not the HTML parser has completed".

I always make use of the

defer

defer

keyword, so I wanted to know some use cases where

async

async

is used, any idea please.