How Purelei increased conversions by +2.3% with Speed Kit

Introduction

Purelei is a fast-growing German jewelry and lifestyle brand, celebrated for its Hawaii-inspired aesthetics and accessible price points. With a loyal community-driven customer base and a fully digital-first retail model, Purelei's online shop is the company's primary revenue channel — making performance, conversion, and user experience central to its commercial success.

Challenge

As Purelei continued scaling its Shopify-based storefront, the team recognized that page speed had become a meaningful constraint on growth. In a market where mobile-first shoppers expect instant page loads, slow load times were directly impacting bounce rates, session engagement, and ultimately, conversions.

Solution

Purelei needed a solution that could deliver measurable speed improvements — without adding engineering overhead or requiring a complex technical integration. That's where Speed Kit came in. Designed specifically for high-traffic e-commerce sites and natively compatible with Shopify, Speed Kit integrates directly via the Shopify App.

No backend changes, no infrastructure work, no significant developer time. The integration was completed quickly, allowing Purelei's team to move from implementation to A/B testing within days.

Results

Speed Directly Drives Commercial Results: The performance improvements translated directly into measurable commercial outcomes. The A/B test data shows a directly observed +2.3% conversion rate uplift between the Speed Kit group and the control group, alongside a projected +3.33% revenue uplift. Together, these figures make a compelling and data-backed business case for a full rollout. Add-to-Cart rates improved by ~9.0% (every 100 ms of LCP improvement corresponds to +1.54% ATC rate), while session length increased by ~10%, meaning faster users visit significantly more pages per session. Bounce rates also fell substantially as load time decreased.

Across All Page Types — Massively Faster Load Times: The performance uplift was consistent and significant across all measured page types. Speed Kit reduced LCP (Largest Contentful Paint) — Google's most important Core Web Vital and a direct SEO ranking signal — by 55% overall, with the median load time dropping from 1,143 ms to just 518 ms. This 625 ms absolute improvement translated directly into a meaningfully better browsing experience for Purelei shoppers. Product pages saw an LCP improvement of 61% (857 ms faster), while collection pages improved by 61% (597 ms faster). These page types are the most critical for conversion — users browsing collections and evaluating products are highest-intent visitors, and the speed gains directly reduce the friction between discovery and purchase.

Instant Navigation Experience: Speed Kit's AI-powered predictive preloading engine pre-cached the next page before users even clicked a link for 78% of all navigations. On product pages — where purchase intent is highest — this figure reached 82%. A full 36% of users experienced pages that were pre-rendered entirely in the background, resulting in near-instant navigation measured at LCP < 300 ms. For product pages specifically, this instant navigation metric improved by +531% compared to the original, reflecting a transformative uplift in perceived speed.

Built for Shopify — Deployed in Days: For Shopify-based merchants like Purelei, the barrier to entry with Speed Kit is exceptionally low. Integration is via the Shopify App — no backend changes, no infrastructure work, no Shopify theme overhaul required. Speed Kit's HTML merge technology ensures cart, account state, and dynamic content remain fully personalized. The Speed Kit team provided hands-on support throughout the rollout — from technical setup to A/B test configuration — ensuring that the Purelei engineering team could remain focused on their core product while Speed Kit handled the performance layer.