In the rapidly evolving world of digital marketing, brands are continually looking for new ways to drive growth and stay ahead of the pack. T-Mobile is the latest in a growing group of market leaders who have recognized that web performance and user experience are not just technical concerns, they’re essential business growth drivers. By prioritizing Core Web Vitals (CWVs) and embedding them into their company-wide strategy, T-Mobile reduced website complaints by 20%, grew their visit-to-order rate by 60%, and increased their cart-to-order rate by 32%.

We’re excited to see Google publishing T-Mobile’s case study, which highlights the significant business benefits of performance-driven user experience optimization. Similarly, Ray-Ban recently adopted a similar approach and achieved a remarkable 156 percent increase in desktop conversions by enhancing on-site functionality to improve speed and user experience. This success has been a major highlight in the performance space. T-Mobile’s story reflects how more brands are prioritizing performance-driven user experiences, and notably, it is paying off.

In this case study, you'll learn:

• How T-Mobile made web performance a cross-team priority

• The data strategy that connected user experience to business outcomes

• How Navigation AI helps businesses scale performance optimization

How T-Mobile made performance a business priority

T-Mobile’s performance journey began with organizational alignment. Their SEO and Product teams collaborated to ensure that Core Web Vitals became a key topic in discussions with stakeholders. Like many companies, they initially encountered a common challenge in the web performance space: demonstrating the importance of prioritizing on-site technical improvements when business teams are focused on sales and marketing goals. Historically, establishing connections between performance and business outcomes has proven to be difficult.

To overcome this hurdle, T-Mobile let data do the talking. They recognized that synthetic tests like Lighthouse scores, which utilize lab data rather than real-user data, would only show part of the picture of how users experienced their site. To understand how performance affected real customers, they integrated the web-vitals JavaScript library directly into their website. This allowed them to measure field data from actual users and connect performance metrics to measurable Key Performance Indicators (KPIs) like Conversion Rates and Bounce Rates. By doing so, T-Mobile uncovered key insights into how users experienced their site, including:

• Visitors were more likely to leave when pages loaded slowly.

• Conversion rates dropped when performance declined.

• There was a direct correlation between revenue impact and each 100-millisecond segment of LCP (loading speeds). 

Source: web.dev

These insights made it clear to everyone that web performance was not just a developer concern. It was a business priority that required cross-team collaboration.

The business impact: Fewer issues and higher conversions

Once the connection between performance and business outcomes was clear, T-Mobile prioritized efforts to improve Core Web Vitals. They focused on three key areas:

• Loading speed (Largest Contentful Paint)

• Visual stability (Cumulative Layout Shift)

• Interactivity (Interaction to Next Paint)

These efforts led to a 42% improvement in LCP, directly enhancing their user experience. The improvements delivered measurable results:

By reducing friction and improving the reliability of their website, T-Mobile created a smoother shopping experience. Customers encountered fewer issues, navigated more easily, and completed more orders.

Scaling web performance improvements to maximize impact

T-Mobile’s performance strategy was designed to address key performance challenges with scalability and long-term sustainability in mind. Their team implemented several technical upgrades that significantly boosted the site's overall performance, including:

Faster data retrieval with API caching

When users browse a site, their actions trigger multiple requests for information (like product details and promotions). Instead of fetching this data from the backend every time, T-Mobile optimized API caching to store frequently accessed data temporarily. This reduced server load and improved response times, ensuring pages loaded quickly without delays.

Efficient static asset delivery

Web pages rely on various supporting files—JavaScript, styles, and client libraries—to display content correctly. T-Mobile reworked how these assets were stored and reused, allowing browsers to load them instantly rather than downloading them repeatedly. This approach cut down on unnecessary data transfers and made navigation smoother.

Optimized images for speed and quality

Large images can slow down websites, particularly on mobile. To solve this, T-Mobile reduced file sizes, adopted modern formats like WebP, and ensured images dynamically adjusted to different screen sizes. This optimization maintained visual quality while significantly improving loading times, especially for mobile shoppers.

Preloading critical resources for faster rendering

Certain essential elements—such as fonts, key scripts, and above-the-fold images—are crucial for a page to load smoothly. T-Mobile implemented preloading techniques to ensure these resources were fetched as early as possible in the loading process. This reduced rendering delays, making pages feel faster and more responsive from the moment users arrived.

These improvements helped T-Mobile’s digital experience become faster, more reliable, and more efficient, resulting in higher user satisfaction and conversion rates.

Processes for continued improvement

As sites continue to evolve, T-Mobile implemented a range of ongoing processes to ensure sustained performance excellence:

Ongoing education and engagement:

Product and SEO teams regularly host knowledge-sharing sessions to emphasize the importance of web performance across teams.

Core Web Vitals alerting systems:

Email alerts are sent to stakeholders when CWVs fall below certain pre-set thresholds.

Performance requirements for code releases:

Pages must meet specified performance standards before launch, ensuring continued web performance excellence.

CWV data for all:

Real-time CWV dashboards and guides are available to all teams, emphasizing the importance of performance throughout the organization.

Why CWVs and performance matter to your business

T-Mobile’s study shows what is possible when companies treat web performance as a business priority. They demonstrated that improving Core Web Vitals leads to real business outcomes, including fewer technical issues and higher conversion rates.

Many businesses acknowledge that performance matters, but struggle to maintain improvements over time. Websites evolve quickly. New content is added, products change, and user behavior shifts. Without the right tools, keeping performance optimized requires constant monitoring and manual effort.

How Navigation AI helps you scale performance optimization

T-Mobile’s success highlights the value of focusing on user experience and web performance. But maintaining these improvements is not always easy. That is where Navigation AI comes in.

Navigation AI helps businesses automate and scale their performance strategy without the need for continuous manual updates. The solution supports long-term optimization through:

Predictive preloading

Navigation AI analyzes real user behavior to predict which pages visitors are likely to visit next. It automatically preloads those pages at the right time, so when a click occurs, the next page is already prepared, reducing wait times and significantly improving the experience. Navigation AI is proven to drive engagement, improve conversions, and boost performance. 

Continuous adaptation

Your website is dynamic. Navigation AI automatically adjusts preloading strategies based on new content, product changes, and evolving user behavior. There is no need to maintain static rules.

Reduced resource requirements

With Navigation AI, you do not need a dedicated team to manage performance improvements. Our technology does the heavy lifting, so your teams can focus on business growth.

Turning performance into business results

By prioritizing Core Web Vitals, measuring real user data, and connecting performance to business outcomes, T-Mobile reduced site issues and increased conversions.

At Uxify, we believe that every business can benefit from this approach. Our mission is to make performance optimization simple, scalable, and focused on real results.

Ready to improve your website’s speed and drive more conversions?
Talk to us today and learn how Navigation AI can help you achieve results like T-Mobile and Ray-Ban.