Hello Akismet Team,

Thanks for a great plugin! I am optimizing my site and would like to help improve Akismet. This plugin currently makes the following request to load a JavaScript file:

<script async="async" src='.../wp-content/plugins/akismet/_inc/form.js?ver=4.1.9' id='akismet-form-js'></script>

So the plugin has hard-coded the async attribute in there. This is definitely better than not using anything.

Both async and defer will load the JS file asynchronously – but using async will interrupt the parsing to run the loaded JavaScript, whereas using defer will not.

With defer, the script will load in the background and then run when the DOM is fully built. So defer is definitely for better to use whenever possible.

The problem is that you cannot defer a script that has already been async’ed (like with Akismet). If you try to specify both (like having an optimization plugin add defer), then the browser will always give async higher priority, thus negating the defer.

So all this is to say that for best optimization and page loading speed, if the Akismet plugin removed async and used defer instead, it would be a better outcome. 🙂

https://flaviocopes.com/javascript-async-defer/

https://javascript.info/script-async-defer

https://stackoverflow.com/questions/10808109/script-tag-async-defer

https://stackoverflow.com/questions/13821151/can-you-use-both-the-async-and-defer-attributes-on-a-html-script-tag

And the defer attribute enjoys very broad browser support:

https://caniuse.com/script-defer

Thanks!

PS – Please also minify your JavaScript file while you’re at it. Appreciate it!