Skip to content

Apr. 26th, 2024

Why site performance matters

Conversion rate and revenue are closely tied to user experience and SEO.

When it comes to site performance, milliseconds make millions in revenue. Improving site performance is essential for retaining visitors, optimizing for search, and achieving business goals such as increased conversions and revenue.

But there’s a lot of thoughtful engineering that goes on behind the scenes to support great site performance.

Learn what site performance is, the technical factors that affect it, and two key benefits of peak performance: user experience (UX) and search engine optimization (SEO).

What is site performance?

Site performance refers to the speed, responsiveness, reliability, and overall efficiency of a website or web app.

Key factors that contribute to overall site performance include:

  1. Page load time: Page load time is the time it takes for a webpage to fully load in a user's browser. Faster load times are associated with better user experiences and higher engagement rates.
  2. Server response time: Server response time is the time it takes for the web server to respond to a request from the user's browser. Optimizing render time ensures that users can quickly access and interact with a page's content.
  3. Resource optimization: Resources optimization is the efficient management of resources such as images, scripts, stylesheets, and other elements. Minimizing file sizes and reducing the amount of data that needs to be transferred between the server and the client speeds up performance.
  4. Caching: Caching is the storage of frequently accessed resources like images, HTML documents, and videos on the client or in intermediate servers. Proper caching techniques can reduce load times for subsequent visits and requests.
  5. User experience (UX): UX is the overall experience of interacting with a website or web application, including factors like responsiveness, ease of navigation, and accessibility. Faster and more responsive sites tend to offer better experiences to users.
  6. Code efficiency: Code efficiency refers to the quality and efficiency of the website's frontend code, including HTML, CSS, and JavaScript. Well-structured, optimized code can improve rendering speed and reduce CPU and memory usage, resulting in better site performance.
  7. Using a content delivery network (CDN): A CDN uses a geographically distributed network of servers to deliver content to users from locations closest to them. CDN utilization reduces latency and improves load times.

Why site performance matters for UX

When it comes to loyalty and brand perception, prioritizing speed and dynamic personalization is crucial to achieving online success.

Brand perception: Users want your site to be fast

Slow load times have a direct impact on user behavior and play into the psychology of consumer sentiment. A fast-loading website conveys quality, efficiency, and reliability, which instills trust in the brand and its offerings.

In fact, latency is the number one reason why consumers decide to abandon mobile sites, with 10% blaming slow downloads as a reason for not purchasing. Plus, when your site is fast, not only do you win and retain customers, but they are more likely to recommend you to others.

45% of consumers say they’re less likely to make a purchase when the site loads slower than expected

Consumers are 26% more willing to recommend an ecommerce site if load times are reduced from 10 seconds to 3 seconds

Dynamic personalization: Users want a unique experience

Users are loyal to brands that they feel “get them.” In a world of countless anonymous digital experiences, a personalized, customizable experience sets your app apart from your competitors.

Historically, dynamic personalization has been at odds with performance due to the use of static pages. Adding dynamism allows you to serve up more personalized content, but often meant slower page loads, especially if your server or data is far away from your user.

A great solution is to use middleware. Middleware allows for multiple versions of pages to be prebuilt, and returns the right page to the right user—you get the benefit of speed alongside the benefit of dynamic personalization.

61% of customers have stopped buying from a company because a competitor provided a better experience

52% of customers go out of their way to buy from their favorite brand, and the best way to ensure application stickiness is with deep personalization

Why site performance matters for SEO: Core Web Vitals

Core Web Vitals affect SEO, and SEO has a direct impact on revenue.

Good site performance directly contributes to better SEO because Google ranks your site, in part, on performance-based metrics: Core Web Vitals.

Google measures Core Web Vitals by observing how real users interact with your website and reporting that back to its servers.

The three metrics that comprise Core Web Vitals are:

1. Largest Contentful Paint (LCP)

LCP measures loading performance: the time it takes for the largest content element, such as an image or text block, to become visible to the user. A fast LCP means users can quickly access and interact with the most significant parts of the webpage, leading to a more engaging browsing experience.

Aim for LCP to occur within the first 2.5 seconds of the page starting to load.

2. Interaction to Next Paint (INP)

INP measures responsiveness: the time it takes for a webpage to become responsive to user input after the main content has loaded. A fast INP ensures users can quickly engage with interactive elements like buttons, links, forms, and menus without experiencing delays or unresponsiveness.

Aim for an INP of less than 200 milliseconds.

3. Cumulative Layout Shift (CLS)

CLS measures visual stability: the unexpected layout shifts that occur as content loads on a webpage, causing elements like buttons, images, or text to unexpectedly move around or "flicker." A low CLS score indicates that the webpage's layout remains stable and predictable, allowing users to interact with content without frustration or confusion.

Aim for a CLS score of less than 0.1.

The impact of SEO on revenue

SEO can have a significant impact on revenue in three key ways:

Increased organic traffic

By optimizing your website for search, you improve its chances of ranking highly on search engine results pages (SERPs). This increased visibility leads to more organic traffic, as users are more likely to click on websites that appear higher in search results. With more traffic comes more potential customers, leading to increased sales and revenue.

Higher conversion rates

Core Web Vitals define a common set of quality signals to measure user experience across the web—so when you optimize Core Web Vitals, you're also optimizing UX. This makes it easier and more enjoyable for visitors to use your site. A user-friendly website is more likely to convert visitors into customers, leading to increased revenue.

Competitive advantage

A strong online presence is essential for staying competitive. Businesses that invest in SEO are more likely to outrank their competitors in search results, leading to increased visibility and market share. This competitive advantage can translate into higher revenue as more customers choose your business over competitors.

Rakuten's improved vitals brought a 53.4% increase in revenue per visitor, 33.1% increase in conversion rate, 15.2% increase in average order value, 35.1% reduction in exit rate, and more.

Yelp reduced First Contentful Paint (75th percentile) by 45% and Yelp Page Complete (75th percentile) by 25% and saw a 15% improvement in their conversion rate.


If a site delights users through personalization and good UX, and is optimized for discovery through search, it will stand apart in a crowded market.

Engineering investments behind the scenes of marketing and ecommerce sites can reap measurable benefits in site performance—and improve your business’s bottom line.

Speed is your bottom line.

Discover how the Frontend Cloud delivers lightning-fast websites that boost your business.

Talk to an Expert

Explore more