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.html526
www.alexrp.co.uk/525
www.alexrp.co.uk/blog/resource-hints-prerender.html526
www.alexrp.co.uk/monitor.html525
www.alexrp.co.uk/blog/web-performance-special-cases.html511
www.alexrp.co.uk/blog/fast-single-page-apps.html517
www.alexrp.co.uk/blog/web-performance-black-friday.html506
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html525
www.alexrp.co.uk/about-web-performance.html505
www.alexrp.co.uk/links.html524

First contentful paint

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html634
www.alexrp.co.uk/blog/preloading-fonts.html685
www.alexrp.co.uk/685
www.alexrp.co.uk/blog/resource-hints-prerender.html685
www.alexrp.co.uk/monitor.html683
www.alexrp.co.uk/blog/web-performance-special-cases.html655
www.alexrp.co.uk/blog/fast-single-page-apps.html675
www.alexrp.co.uk/blog/web-performance-black-friday.html654
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html684
www.alexrp.co.uk/about-web-performance.html652
www.alexrp.co.uk/links.html682

DOMContentLoaded

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html783
www.alexrp.co.uk/blog/preloading-fonts.html849
www.alexrp.co.uk/849
www.alexrp.co.uk/blog/resource-hints-prerender.html850
www.alexrp.co.uk/monitor.html845
www.alexrp.co.uk/blog/web-performance-special-cases.html821
www.alexrp.co.uk/blog/fast-single-page-apps.html834
www.alexrp.co.uk/blog/web-performance-black-friday.html811
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html846
www.alexrp.co.uk/about-web-performance.html810
www.alexrp.co.uk/links.html841

Onload

PageMedian (ms)
www.alexrp.co.uk/blog/speed-index-and-ux.html1129
www.alexrp.co.uk/blog/preloading-fonts.html1258
www.alexrp.co.uk/1258
www.alexrp.co.uk/blog/resource-hints-prerender.html1258
www.alexrp.co.uk/monitor.html1256
www.alexrp.co.uk/blog/web-performance-special-cases.html1201
www.alexrp.co.uk/blog/fast-single-page-apps.html1232
www.alexrp.co.uk/blog/web-performance-black-friday.html1182
www.alexrp.co.uk/blog/ab-testing-and-web-performance.html1256
www.alexrp.co.uk/about-web-performance.html1178
www.alexrp.co.uk/links.html1249

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 Short bars indicate retrieved from cache
www.alexrp.co.uk/fonts/fontos.woff2
www.googletagmanager.com/gtag/js?id=UA-148024686-1
platform.twitter.com/widgets.js
platform.linkedin.com/in.js
www.alexrp.co.uk/images/img-ahead-of-font.png
www.alexrp.co.uk/images/banner-576.jpg
platform.twitter.com/widgets/widget_iframe.96fd96193cc66c3e11d4c5e4c7c7ec97.html...
www.google-analytics.com/analytics.js Short bars indicate retrieved from cache
www.google-analytics.com/j/collect?v=1&_v=j87&a=1840972929&t=pageview&_s=1&dl=ht...
platform.twitter.com/js/button.63c51c903061d0dbd843c41e8a00aa5a.js Short bars indicate retrieved from cache
Time:1s2s3s4s5s...