How this site performs

This page contains web performance stats for this website. It's taken from real user monitoring, which I've added using Boomerang.

Real user monitoring works by sending a beacon containing performance data for every visit to a page on the site. This makes it a good way to gain insights into the experience a website delivers.

Not every test reports on every metric – for example, some browsers don't support first contentful paint.

I've just picked out a few metrics to highlight on this page.

Response start

When the first byte of data is delivered to the browser.

First contentful paint

This aims to measure the point at which people can begin to consume content on the page.

DOMContentLoaded

The DOM and CSSOM are likely to be ready at this point. DOMContentLoaded can be important because some scripts will wait for this event before executing.

Onload

The time it takes for all the resources on the page to finish loading – although this excludes script-injected assets that are fetched only when the onload event has fired.

Response start

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html475
www.alexrp.co.uk/blog/preloading-fonts.html485
www.alexrp.co.uk/485
www.alexrp.co.uk/blog/resource-hints-prerender.html483
www.alexrp.co.uk/monitor.html478
www.alexrp.co.uk/blog/web-performance-special-cases.html475
www.alexrp.co.uk/blog/fast-single-page-apps.html479
www.alexrp.co.uk/blog/web-performance-black-friday.html478
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html480
www.alexrp.co.uk/about-web-performance.html480
www.alexrp.co.uk/links.html476

First contentful paint

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html613
www.alexrp.co.uk/blog/preloading-fonts.html633
www.alexrp.co.uk/633
www.alexrp.co.uk/blog/resource-hints-prerender.html633
www.alexrp.co.uk/monitor.html626
www.alexrp.co.uk/blog/web-performance-special-cases.html613
www.alexrp.co.uk/blog/fast-single-page-apps.html627
www.alexrp.co.uk/blog/web-performance-black-friday.html627
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html627
www.alexrp.co.uk/about-web-performance.html627
www.alexrp.co.uk/links.html623

DOMContentLoaded

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html753
www.alexrp.co.uk/blog/preloading-fonts.html770
www.alexrp.co.uk/770
www.alexrp.co.uk/blog/resource-hints-prerender.html770
www.alexrp.co.uk/monitor.html763
www.alexrp.co.uk/blog/web-performance-special-cases.html753
www.alexrp.co.uk/blog/fast-single-page-apps.html763
www.alexrp.co.uk/blog/web-performance-black-friday.html763
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html764
www.alexrp.co.uk/about-web-performance.html765
www.alexrp.co.uk/links.html758

Onload

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html1081
www.alexrp.co.uk/blog/preloading-fonts.html1110
www.alexrp.co.uk/1106
www.alexrp.co.uk/blog/resource-hints-prerender.html1102
www.alexrp.co.uk/monitor.html1089
www.alexrp.co.uk/blog/web-performance-special-cases.html1082
www.alexrp.co.uk/blog/fast-single-page-apps.html1093
www.alexrp.co.uk/blog/web-performance-black-friday.html1090
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html1093
www.alexrp.co.uk/about-web-performance.html1094
www.alexrp.co.uk/links.html1086

Resource timings for latest test

The following waterfall chart is taken from the most recent test (excluding tests of this page) and gives an indication of how long it took to load the resources on that page.

www.alexrp.co.uk/blog/preloading-fonts.html
www.alexrp.co.uk/css/common-v2.css
www.alexrp.co.uk/fonts/fontos.woff2
www.googletagmanager.com/gtag/js?id=UA-148024686-1
www.alexrp.co.uk/images/img-ahead-of-font.png
www.alexrp.co.uk/images/preload-930.png
www.alexrp.co.uk/images/font-film.png
www.alexrp.co.uk/images/devtools-no-preload-860.png
www.alexrp.co.uk/images/devtools-preload-860.png
platform.twitter.com/widgets.js
www.alexrp.co.uk/images/feed-icon-28x28.png
www.alexrp.co.uk/images/banner-2560.jpg
www.google-analytics.com/analytics.js
platform.twitter.com/widgets/widget_iframe.4f8aea4342a4ada72cba2bdffcff6b4d.html...
www.google-analytics.com/r/collect?v=1&_v=j79&a=142698832&t=pageview&_s=1&dl=htt...
platform.twitter.com/js/button.550007e6cc79c00bac51111d8131d860.js
platform.twitter.com/widgets/tweet_button.4f8aea4342a4ada72cba2bdffcff6b4d.en.ht...
Time:1s2s3s4s5s...