Less haste, more speed. Why publishers should stop looking at load times

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.

Don’t believe us? Well just ask Google: All of Google’s 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, “Load is not a single moment in time — it’s 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].

The problem with load time

Page load time isn’t 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’s point of view.

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.

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.

Useful speed performance metrics from Publisher Ads Audits for Lighthouse Beta

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’ll 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.

First Contentful Paint

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

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 of the page beginning to load.

Time to Interactive

Time to Interactive (TTI) measures the amount of time it takes for a page to become “interactive.” For example, how long until the page responds to a click. This metric is defined by three points:

• When the First Contentful Paint occurs
• When the most visible elements on the page become interactive and responsive
• When the page responds to user interactions within 50 millisecond

It is suggested that a good TTI is less than five seconds when tested on average mobile hardware.

Speed Index

Speed Index is a metric that measures in milliseconds how long it takes for visible parts of the page to be painted on screen. The lower the figure, the better the performance. Speed Index takes into consideration the visual completeness of the above-the-fold section of the page. There is no defined benchmark for Speed Index, but a score of less than 1000ms is considered as acceptable.

How to view speed performance metrics in Publisher Ads Audits for Lighthouse Beta

1. Navigate to a website that uses Google Ad Manager and run a report using Google Publisher Console. To learn more about Publisher Console and how to run a report, check out our three-part video guide.
2. Click on the ‘Audit this Page’ tab in the top right corner.
3. In the middle of the page, there is a performance report. The aforementioned speed performance metrics will be shown in the left-hand column.

It is important to note that Lighthouse audits one single page at a time and therefore, these metrics are not representative of your entire website. Just because your homepage loads quickly, it does not mean that the rest of your site will.

Final Thoughts

To summarise, although load time is looked at by publishers as a well-defined stage in a page’s lifecycle, it does not necessarily correspond to the user experience. We recommend not optimising content visibility at the expense of interactivity as this is what users generally care about.

It is also worth noting that Google search algorithms also take into account how much time passes before users are able to interact with content. This means that the speed performance of your website will affect your overall SEO ranking. Therefore, if you take steps to reduce the time taken, it is likely that your site ranking will improve. If your web pages load slowly, this will reduce your ad quality score and cause ads to be more expensive.