How Erwin Müller increased conversions by +1.74% with Speed Kit
Published on April 17, 2026
- Retail
- Europe
- Custom
+1.74%
Conversion rate uplift
+2.29%
Projected revenue uplift
81%
Traffic loads within 1 s
“The data is unambiguous: a +1.74% conversion rate uplift and a projected +2.29% revenue increase from a single performance integration. What made this possible was the depth of expertise the Speed Kit team brought to the table. They didn't just deploy a solution - they ran a thorough RUM analysis, identified specific INP bottlenecks on mobile, and showed us exactly what needed fixing. That kind of proactive, data-driven partnership is what turns good results into outstanding ones.”
Introduction
Erwin Müller is one of Germany's most established home and lifestyle retailers, offering a comprehensive range of textiles, bedding, bath products, tableware, and home decor. With a heritage built on quality, reliability, and a deep understanding of customer needs, Erwin Müller has successfully grown its digital presence into a primary revenue channel, serving millions of shoppers through de.erwinmueller.com.
Challenge
As the expectations of online shoppers have risen sharply, Erwin Müller recognized that page load performance had become a critical differentiator. Mobile users in particular expect fast, smooth browsing experiences — and any friction in the journey from landing to checkout has a direct and measurable impact on conversion and revenue. Addressing this at scale, without disrupting existing systems or burdening the engineering team, required a targeted and proven solution.
Solution
Speed Kit was deployed to tackle this challenge head-on. Through a rigorous 50/50 A/B test running from February 4 to February 25, 2026, Speed Kit demonstrated clear and consistent improvements in load times, user engagement metrics, and most importantly, significant commercial results.
Results
Speed Directly Drives Commercial Results: The performance improvements translated directly into measurable commercial outcomes. The A/B test data shows a directly observed +1.74% conversion rate uplift between the Speed Kit group and the control group, alongside a projected +2.29% revenue uplift. Together, these figures make a compelling and data-backed business case for a full rollout across de.erwinmueller.com. Session length improved by 2.3% — with every 100 ms of LCP improvement corresponding to a +1.58% increase in session length, meaning faster users navigate significantly more pages per visit. Bounce rates also fell substantially as load times decreased, further reinforcing the commercial case.
Interaction to Next Paint (INP): After the fix provided by Speed Kit's in-house Google Developer Experts in web technologies, the INP on mobile has risen from 19% to 95% green.
Category Pages — The Most Impactful Uplift: Category pages are the primary discovery and browsing surface for Erwin Müller's shoppers. LCP improved by 41% — 214 ms faster at the median, dropping from 522 ms to 308 ms. Faster category browsing means more products considered, longer sessions, and a shorter path to purchase.
Instant Navigation — 81% of Traffic Loads in Under 1 Second: With Speed Kit, 81% of all page loads now complete within 1 second, a threshold that defines a genuinely fast experience for users. Even more striking: the share of pages loading within 300 ms has tripled compared to without Speed Kit.
