WebPageTest results

Summary

First view Repeat view
Page Speed index First byte Start render Load Bytes Requests Connections Speed index Load
Times are in milliseconds and are the median values from 9 runs in WebPageTest. The test location was Dulles, the connection was Native Connection and the browser was Chrome. All measurements were taken between 10:40:15 AM and 10:50:50 AM on 4/17/2015.
Nature homepage 1,400 171 1,393 1,958 433,075 53 26 1,000 2,455
Nature article 1,952 717 1,693 3,096 880,916 73 37 1,511 2,295
CNN homepage 4,080 134 2,792 8,077 2,352,917 132 75 2,243 5,863
CNN article 3,908 128 2,395 6,758 2,571,425 180 98 1,894 4,738

Care should be taken when making comparisons between the figures for different pages, since each page contains a different amount of data and requires a different amount of work. Nonetheless, some comparisons can be made.

Charts

Speed index, first view

Speed index, first view Nature homepage 1,400 Nature homepage Nature article 1,952 Nature article CNN article 3,908 CNN article CNN homepage 4,080 CNN homepage First-view speed index (lower is better)

Speed index, repeat view

Speed index, repeat view Nature homepage 1,000 Nature homepage Nature article 1,511 Nature article CNN article 1,894 CNN article CNN homepage 2,243 CNN homepage Repeat-view speed index (lower is better)

Speed index, repeat-view improvement

Speed index, repeat-view improvement CNN article 48% CNN article CNN homepage 55% CNN homepage Nature homepage 71% Nature homepage Nature article 77% Nature article Repeat-view speed index as a percentage of first-view (lower is better)

First byte

First byte CNN article 128 CNN article CNN homepage 134 CNN homepage Nature homepage 171 Nature homepage Nature article 717 Nature article Time to first byte (milliseconds)

Start render, difference from first byte

Start render, difference from first byte Nature article 976 Nature article Nature homepage 1,222 Nature homepage CNN article 2,267 CNN article CNN homepage 2,658 CNN homepage Time from first byte until start render (milliseconds)

Load, difference from first byte

Load, difference from first byte Nature homepage 1,787 Nature homepage Nature article 2,379 Nature article CNN article 6,630 CNN article CNN homepage 7,943 CNN homepage Time from first byte until load event (milliseconds)

Optimisations

Page First byte Persistent connections GZIP compression Image compression Progressive JPEGs Browser caching Asset CDN
Nature homepage 90% 94% 100% 78% 0% 37% 64%
Nature article 37% 96% 100% 64% 9% 47% 55%
CNN homepage 95% 100% 99% 83% 0% 53% 93%
CNN article 97% 93% 99% 69% 0% 54% 93%