The Importance of Improving Website Performance

December 16, 2021 Mihaela Lica Butler

Website performance describes how fast a website loads in the browser and how fast its processes respond to user interaction, therefore web accessibility. Moreover, website performance will impact your rankings in the search engines and affect user experience, eventually affecting user retention and conversion rates.

Top Reasons for Improving Website Performance


The main reason to improve website performance is meeting site visitors’ needs. For this, you must consider the devices they use when accessing your website. A large site may load fast on a desktop, but more and more users worldwide have tablets or smartphones and access websites on mobile networks. Sites created for desktop PCs may load slower on these devices, if not at all, impacting the user experience negatively, which may be bad for your Google rankings. But more importantly, there are still many countries that charge per megabyte for Internet access with mobile phones, and users in these countries will pay a premium to access a sluggish website. To find out just how much, test your site with What Does My Site Cost? - a tool that will also indicate why, although you target certain countries with localized content, your site doesn’t attract the number of visitors you expected.

Page Speed Is a Google Ranking Factor

Page load time or page speed is a primary ranking factor. Therefore, failing to improve page and website speed will impact your SEO negatively. The page load time may negatively impact your site speed too. It is one of the latency aspects to consider when improving your website performance. Google provides PageSpeed Insights for website admins to evaluate how fast their web pages load on different devices. It also offers a suite of other PageSpeed tools for webmasters to optimize the speed of their sites.

Besides the page load time, to determine the site speed, Google considers execution speed for user interactions and how quickly the browser parses the page and makes it available for user interaction.

Page speed is a ranking factor for desktop since 2010 and mobile since 2018, when Google announced its “Speed Update.”

Page Experience Is a Google Ranking Factor

How users perceive the experience of interacting with a web page is part of Google’s ranking systems since June 2021. Google announced rolling out the "page experience update" in November 2020, and by the end of August 2021, it will finish rolling out to all the users and websites. As you can see in the image below, loading is one of the core signals for page experience.

Page Experience Signal The page experience will be one of the most important SEO factors in 2021 and beyond. Here are some of the things Google will consider from now on when ranking websites:

  • Largest Contentful Paint (LCP), which is a signal measuring the render time of the largest text block, image, or video visible within the viewport after the page first started loading. You should aim for an LCP of 2.5 seconds or lower.
  • First Input Delay (FID) measures load responsiveness and how users interact with unresponsive pages. FID should be under 100 milliseconds delay to provide a good user experience.
  • Cumulative Layout Shift (CLS) is a user-centric metric that measures the visual stability of a website’s content.
  • Mobile-friendliness - since more and more users access the web via mobile devices, it makes no sense for your website not to be mobile-ready.
  • Safe browsing: scan your site regularly to see whether it was hacked or contains spyware or malware.
  • Secure HTTPS connection.
  • Zero tolerance for intrusive interstitials - like junk popup ads, banners, and overlays, that take away from the user experience.


Improve User Retention and Conversions

Improving user retention is the cornerstone of improving conversions. Whether you create a website to sell products or services, gain readers (blog posts, online magazines), or build a community, you cannot achieve your goals without visitors and convert those visitors into dedicated users.

These dedicated users are the ones who will take action on your site: buy, book, download, subscribe to newsletters, read your articles or blog posts, watch videos, and so on. These actions are conversions. The more dedicated the users, the higher the conversions.

An underperforming site drives users away.  According to Google, the slower loading a site is on mobile devices, the higher the bounce rate, which leads to fewer conversions. Therefore, the probability for visitors to bounce off a page increases as follows:

  • by 32% when the page load time goes from 1 second to 3
  • by 90% when the page load time goes from 1 second to 5
  • by 123% when the page load time goes from 1 second to 10

Mobile Page Speed Data

Performance is critical for conversions.

  • 79% of online shoppers will avoid an online retailer where they have experienced performance issues (source: Envisage Digital)
  • 70% of consumers say that page speed impacts their willingness to buy from an eCommerce site (source: Unbounce)

To improve conversions and retain users, you must improve website performance right now. Ideally, aim for a site that loads in less than two seconds regardless if your content aims to satisfy desktop or mobile users.