My CDN score used to be a “C”, but now it is an “F” yet I use MaxCDN now which was the same as before when I was a “C”…what could of changed? Secondly, would a sprite combine my js and css files…don’t know much about that yet. Finally, what is the red solid line that is coming from a third party image on my site…do I need to contact the vendor for that plugin? http://www.webpagetest.org/result/100718_1HF6/
Do you have a link to your latest results? That way we can all be talking to the same tihing.
The red line is an error (something failed to load) - probably a 404 response. If it is being served by a 3rd party then yes, you should probably ping them. If it is for an image then you’d have a broken image on the page, if it was for something else then the result depends on what it is.
A sprite will combine images together but doesn’t do anything for css and js - those are actually a LOT easier to combine since you can just merge the files together (though on a publishing platform like wordpress it is more difficult which is why there are plugins that can do it for you).
The CDN grade is a percentage of static requests that are served from a CDN. If you reduce the requests you control (which is a good thing) then the percentage of requests that are served by the 3rd party non-CDN actually goes up and makes your grade worse. This is one of the reasons I’m not a big fan of the grades because optimizing for the grades might end up backfiring.
Yeah, you probably want to contact the plugin company because it looks like the failed request is a malformed url (and may actually have messed up the html) - http://mls-photos.div%3c/li%3E%3Cli%20class=
It looks like there is still some work you can (or need) to do to get the CDN working for the images on your site. All of these failed and look like they are ones you control:
It looks like there is a wordpress setting for the uploaded files that lets you specify the url that they are referenced from (Full URL path to files) - you need to change that to point through your maxcdn url and then all of the uploads should be served from the CDN.