Critical Path (above-the-fold) CSS manager.
Move the regular CSS to the footer if Critical Path management is activated.
Options to activate or disable for home page, product pages and category pages separately.
Low risk. Activating all options will not break the layout.
Get your above-the-fold CSS from one of the online generators, paste it into the manager, save and you are done.The data you need to submit can conveniently be obtained in the admin.
Remove unused CSS.
As a bonus you receive the option to use clean css from unused CSS rules.
Here also you can choose to do home-, category- or product pages separately.
If on a page the critical path CSS is used, you can choose an option to replace the regualr CSS in the footer by cleaned CSS (Uncss). This saves up to 80% in file size, Especially in Bootstrap-based themes.
Please note: This option however should be used with care. On heavily styled sites, when category or product pages differ from each other, you will only be able to use it on the home page.