The heat map below indicates at what time each pixel realised (and maintained) its final state. It works by analysing the filmstrip images generated by webpagetest.org.
Green elements are the fastest to render, red elements are the slowest, relative to a 9.8 second budget.
This is a proof-of-concept on top of webpagetest.org, not a complete tool, so please give me feedback!

0.0s1.7s2.5s3.6s3.8s4.2s4.5s4.6s7.6s7.9s8.1s9.7s9.8s10.0s10.2s10.4s
0%37%60%64%67%71%78%86%88%90%91%99%99%99%99%100%
Set BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet BudgetSet Budget
URL
Tested
Location
Location
Connectivitybps download, bps upload, ms latency
Visually Complete0.0s
SpeedIndex