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To be clear - Pagespeed Insights does not measure the speed of a page, It's entirely possible to have a score of 90 and a load time of (a disastrous) 29 seconds. I have screenshots to prove it All Pagespeed does is check for the typical server/software configurations that "usually" lead to faster pages, as Linda mentions. All you should care about is what your VISITORS experience and what they think is "fast enough". You need to put RUM (Real User Monitoring) on the site's pages so you can directly correlate visitor behaviour/conversions to page speed. (And so you'll actually know what speed real users experience, as opposed to the totally synthetic speed tests like Pagespeed Insights or even webpagetest.org/gtmetrix etc.) If the site uses Google Analytics, this RUM is built in, but you must adjust the tracking code snippet to get worthwhile value from it. By default, Analytics will only track 1% of pageviews' speed. Adjusting the tracking snippet will allow tracking of up to 100% of pageviews or 10,000 pageviews per day. You'll have SERIOUS power in your hands when you can see the actual speed performance of all pages that takes into account REAL user variables like connection speed, location, browser, mobile vs. desktop, time of day/server load etc, etc. Don't guess - use data. Hope that helps? Paul P.S. If the site does have really high-volume traffic, you will already have at least a bit of data in the Site Speed report in GA at teh defualt 1% You can use it as a baseline to prompt action and to measure improvements, but you want to get up to that 10,000 pageviews tracked per day as soon as possible.