You can activate various levels of the plugin, from conservative to very aggressive. Though on rare occasions some feautures could not work well with some templates or extensions, it is well worth trying it out, and see which features work well. Make sure to check the speed of your website before and after with performance tools. You could be surprised by the results. Personally, it helped me to gain 100% scores in the Google Pagespeed Tool and Pingdom Tools.
First of all, download, install and activate the plugin. Then access the plugin and start configuring. In the Basic Options tab you see a set of presets that you can use:
For many users these presets may work fine, but personally I like to know exactly what I am doing. Lower down the page you see the Automatic Settings Group (click the text to open it up, this is sometimes not clear to everyone). These settings are first set based on the preset you chose, but you can also customize them manually:
The features in the Pro tab are not available for free users, but they offer even more functionality. I found those features very usefull. It concerns the following options:
Finally, in the Optimize Images tab (only Pro-users), you will find an option to optimize your images with lossless compression and also a resize option:
This option only works if you have filled in your Download ID, as it connects to a service (Kraken.io I believe) and your ID is used for the API.
Make sure to check your site carefully after optimization. As said, sometimes stuff breaks without noticing right away. Possible issues can be:
The plugin can be downloaded and used for free, which is fine for many sites. The Pro-package contains some very interesting extra's though, so it's worth the money. You can buy subscription packages from $29 for half a year to $99 for lifetime access. This last one is probably the best value for money.
If you want you can also check a Youtube video about the plugin that I created:
By the way, you can find my full video series of Joomla Performance here on Udemy.com: https://www.udemy.com/joomla-performance-and-speed/?couponCode=JOOMLA-SEO
Joomlaseo.com is fully built and written by Simon Kloostra, SEO Specialist and Webdesigner from the Netherlands. I have also published the Joomla 3 SEO & Performance SEO book. Next to that I also sometimes blog for companies like OStraining, TemplateMonster, SEMrush and others. On the monthly Joomla Community Magazine I have also published a few articles.