Why can't I find the PageSpeed Critical Path Explorer anymore?
The critical path explorer tool is no longer available as part of PageSpeed Insights. Although the critical path is important for understanding web performance, we have decided to re-think the feature in PageSpeed Insights. In the meantime, we suggest following the recommendations under the new Eliminate external render-blocking Javascript and CSS in above-the-fold content rule in PageSpeed Insights which lists the critical path resources for the page.