{"id":5736,"date":"2020-03-24T10:57:36","date_gmt":"2020-03-24T10:57:36","guid":{"rendered":"https:\/\/oko.uk\/?p=5736"},"modified":"2020-03-24T10:57:36","modified_gmt":"2020-03-24T10:57:36","slug":"speed-performance-metrics","status":"publish","type":"post","link":"https:\/\/cool.co\/supply-side-platform-home\/speed-performance-metrics\/","title":{"rendered":"Less haste, more speed. Why publishers should stop looking at load times"},"content":{"rendered":"

When looking to improve page performance, many publishers look firstly at reducing the loading time of their page. It seems logical – faster loading pages equals happier users? The truth is that load times are no longer a great measure of how users perceive load time and there are now far better ways to measure it.<\/p>\n

Don\u2019t believe us? Well just ask Google: All of Google\u2019s metrics around page performance have moved away from load times in recent years. They understand that what is really important is user perception of speed: When they see content and how long before they can interact with a page. As they put it, \u201cLoad is not a single moment in time \u2014 it\u2019s an experience that no one metric can fully capture. There are multiple moments during the load experience that can affect whether a user perceives it as “fast” or “slow” [source<\/a>].<\/p>\n

The problem with load time<\/h2>\n

Page load time isn\u2019t without value, but it can be very misleading and less useful than some other easily obtained speed performance metrics. Page load time looks at how long it take for every element of a page to complete loading. From a technical perspective that is an accurate measure of speed, but it makes little sense from a user\u2019s point of view.<\/p>\n

If a user can see the page content and interact with that page then they will generally consider it to have loaded. The fact that a status message in the bottom corner of the browser indicates that something is still loading is of little importance to a user who can now do what they set out to do.<\/p>\n

It certainly is good practice to reduce overall load times (particularly for mobile users who may have limited or expensive data), but it is not a reliable indicator of user speed perception. After all, when you stream a film on Netflix you are only concerned with how long it takes to start playing not when the background streaming ends.<\/p>\n

Useful speed performance metrics from Publisher Ads Audits for Lighthouse Beta<\/h2>\n

There are three user-centric speed performance metrics in Publisher Ads Audits for Lighthouse Beta that can be used to measure how users experience the performance of a web page. We\u2019ll be using speed performance metrics from Publisher Ads Audits for Lighthouse Beta because this looks specifically at how ads load and takes into account the expectations around an ad-funded website.<\/p>\n

First Contentful Paint<\/h3>\n

First Contentful Paint (FCP) measures the time from when the page starts to load to when the first part of the page\u2019s content is rendered on screen. This includes consumable information such as text, images or canvas elements.<\/p>\n

As the focus is on content, this metric aims to better represent user-experience with regards to load time. It is recommended that sites should aim to have the FCP to occur within one second<\/a> of the page beginning to load.<\/p>\n

Time to Interactive<\/h3>\n

Time to Interactive (TTI) measures the amount of time it takes for a page to become \u201cinteractive.\u201d For example, how long until the page responds to a click. This metric is defined by three points:<\/p>\n