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.html488
www.alexrp.co.uk/blog/preloading-fonts.html490
www.alexrp.co.uk/488
www.alexrp.co.uk/blog/resource-hints-prerender.html489
www.alexrp.co.uk/monitor.html487
www.alexrp.co.uk/blog/web-performance-special-cases.html488
www.alexrp.co.uk/blog/fast-single-page-apps.html479
www.alexrp.co.uk/blog/web-performance-black-friday.html488
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html488
www.alexrp.co.uk/about-web-performance.html488
www.alexrp.co.uk/links.html476

First contentful paint

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html634
www.alexrp.co.uk/blog/preloading-fonts.html635
www.alexrp.co.uk/635
www.alexrp.co.uk/blog/resource-hints-prerender.html635
www.alexrp.co.uk/monitor.html634
www.alexrp.co.uk/blog/web-performance-special-cases.html634
www.alexrp.co.uk/blog/fast-single-page-apps.html627
www.alexrp.co.uk/blog/web-performance-black-friday.html634
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html634
www.alexrp.co.uk/about-web-performance.html635
www.alexrp.co.uk/links.html623

DOMContentLoaded

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html783
www.alexrp.co.uk/blog/preloading-fonts.html787
www.alexrp.co.uk/785
www.alexrp.co.uk/blog/resource-hints-prerender.html786
www.alexrp.co.uk/monitor.html777
www.alexrp.co.uk/blog/web-performance-special-cases.html782
www.alexrp.co.uk/blog/fast-single-page-apps.html763
www.alexrp.co.uk/blog/web-performance-black-friday.html780
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html782
www.alexrp.co.uk/about-web-performance.html785
www.alexrp.co.uk/links.html758

Onload

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html1129
www.alexrp.co.uk/blog/preloading-fonts.html1130
www.alexrp.co.uk/1130
www.alexrp.co.uk/blog/resource-hints-prerender.html1129
www.alexrp.co.uk/monitor.html1125
www.alexrp.co.uk/blog/web-performance-special-cases.html1129
www.alexrp.co.uk/blog/fast-single-page-apps.html1093
www.alexrp.co.uk/blog/web-performance-black-friday.html1128
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html1129
www.alexrp.co.uk/about-web-performance.html1129
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.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/banner-2560.jpg
platform.twitter.com/widgets/widget_iframe.7aeb03ce9f308997020e5998720fbbf7.html...
Time:1s2s3s4s5s...