WordPress Speed Up Service | WordPress Website Maintenance Packages Reply To: How to take advantage of browser cache?, by Steve Stern autoptimze concatenates and minifies CSS and JS, it doesn’t cache anything. So your server should cache the output of autoptimize (that’s really hard to type correctly!) and improve performance for your site. If your server does caching, you probably should not use a caching plugin. Evaluate your site as a human. Does it seem to load quickly? If so, good. Forget about what the various speed tests say. You build your site for humans to use, not to impress Google. Reply To: How to take advantage of browser cache?