To attain speeds better than 0.5s load time, we need to start thinking differently:
First, for the first time in a long time, we have to think about the actual process by which a page is retrieved, transmitted, and then stored. It turns out that we are looking at wait times on the order of 71ms or thereabouts when we make more than one request. At the order of 500ms this is significant. So, we drop them off one by one.
Although there is discussion about whether or not to include the css inline at this stage, or to keep it as a separate file, we are interested here in the absolute minimum attainable on the available equipment. So we put minified css inline, and then try to reduce the size of that file as much as possible, by removing unnecessary lines.
Second, we then determine that, yes, we are able to translate an image into an SVG (scalable vector graphic) format (this hearkens back to the days of Postscript, which was essentially the same thing), and then include that directly into the the text stream of the main file (cool). Although it takes up a lot of space visually, the text is compact and fairly easy to scroll past if we wish to look at the raw html source file.
Third, we realize we have to drop the analytics script, as we assume that is also costing us about 100ms.
Fourth, we have to translate the information contained in an image to a table format. We try to place the favicon in the root folder, but then find that this behaviour is discouraged. After retaining the link to the favicon, and placing it in the theme folder, we find out that we are not penalized for this. The call is not counted for that file.
And finally, we realize that the relative links to the font file we have included in our css files have to be hard coded in and include the full domain, or they would not work when the css is placed within the document itself.
When all of that is said and done, we are left with a file that is just over 19kb in size, which is quite small, actually. When thinking about that and trying to decide whether or not to go with an external css file, it seems to be that including the file in the text of of the page would (a) prevent the need for a cdn, and therefore be of assistance for requests coming across the globe, (b) allow for a single sequential disk read and disk write (think tape drive here), and (c) allow for a single stream of information being transmitted over the internet from one location to the next.
I told you it wasn’t easy! Got that? Great, now you know how to do it on your own. If you don’t, here is a pricing page that describes various levels of service, all the way up to high end performance sites.
Getting this far on the WordPress platform has taken the better part of a year, so even for the premium package at $9,995, your are still getting value for your dollar, if you compare that against having to start from scratch.