Speed performance on mobile
My website is www.pianomaster.org
I found that the appointment theme makes the whole website a lot slower than for example the twenty seventeen theme from wordpress. The google PageSpeed Insights gives a rating of 61/100 for mobiles with the appointment theme while I get 89/100 using twenty seventeen theme. This is pretty significant especially since Google announced that they would, starting this month, take in account the PageSpeed rating in their ranking factors.
Now, using some optimization plugin like W3 Total Cache has proven quite effective for the PageSpeed rating for PC screen : it went from 78/100 to 89/100. But it has not been as efficient for PageSpeed rating for mobile. It went from 61/100 to 70/100 which is not decent enough.
My webpage is very simple. You can see that the problem essentially comes from the way the appointment theme works : It loads all CSS styles, including below the fold, as soon as you load the page.
So the question is, and I think it matters a lot : how can you optimize the performance of the appointment theme for mobile use ?