Optimum setting. The plugin will then
it at the bottom of the document just before the
</body> tag and adds the
async attribute to the
Excluded files will not be deferred.
If you're excluding files however while maintaining the original execution order of files on
the page, then this behaves differently. The plugin will
split the combined file around the excluded files or scripts
and place the defer attribute
only on the
<script/> at the bottom of
the page. Read the section above called, Excluding files and declaration blocks, to
better understand this behaviour.
Please note the excluded files and the combined files above the excluded files will not be deferred!
If you exclude files without maintaining the original execution order of the files on the page and the excluded files have dependency relationships on other files that are combined you will most likely break your page. If you're not sure then do not exclude files in this manner!
Dynamically loaded files cannot be deferred.
If you're not excluding files and using the
Optimum setting but you're
still seeing this issue being triggered on GTmetrix or on PageSpeed Insights then most likely this is
caused by files that are being loaded dynamically using
embedded in the HTML so the plugin cannot access these files
to optimize and combine them.
Most times, ironically, these files tend to be Google Analytics, Google Maps, Google Ad files, or social media files. Check the HTML source for the links of the files that are triggering this error. If they are not in the source then it means they were loaded dynamically. In this case there's nothing the plugin can do to address this. The only remedy unfortunately is to avoid using the applications that load these files on your site or on your landing pages to the best extent possible.