How Kastner & Öhler increased conversions by +3.47% with Speed Kit
Published on October 20, 2026
- Fashion
- Europe
- OXID eShop
+3.47%
Relative uplift in user conversion rate during the PoC phase
49%
Faster Largest Contentful Paint on the accelerated pages in Austria
75%
Faster Time to First Byte on the accelerated pages in Austria
“Speed Kit delivered exactly what was promised, a measurably faster experience for our customers with no disruption to our operations. The results from the test were compelling enough to move forward with confidence.”
Introduction
Kastner & Öhler is one of Austria's leading fashion retailers, with roots dating back to 1873. The family-owned company operates 15 fashion stores across Austria, including its landmark flagship store in Graz, and serves customers across Europe through its online shops in Austria, Germany, Switzerland, France, Spain and Italy. With Speed Kit, the main content on the accelerated pages in Austria now loads 49% faster, and during the PoC phase the user conversion rate in the German shop rose by 3.47% compared to the control group.
Challenge
Kastner & Öhler's online shops for Austria, Germany and Switzerland run on one technical base. The shops already passed Google's Core Web Vitals, and performance analysis identified opportunities to improve server response times and load times further, particularly on product and category pages. Performance kept returning to the top of the list, and the team wanted to know what it is worth in conversions, so that the management board would have a clear basis for a decision. The digital experience was to reflect the same high standards as the in-store experience, and whatever went into the shop had to be safe, so that the shop keeps working as before if the service is ever unavailable.
Solution
Speed Kit is embedded directly in the page header of the existing shop and runs on top of it without changes to the shop itself. It works out which page a visitor is likely to open next and prepares it in the background, so the next product or category page is often already complete when the customer clicks. If Speed Kit is ever unavailable, the shop is served as before. The rollout started on the Swiss shop with a small share of traffic, then all three shops ran a PoC phase with half of the visitors in an unaccelerated control group. After the PoC, Kastner & Öhler decided to continue with Speed Kit.
Results
Business Impact — PoC Phase: During the PoC phase, half of the visitors on kastner-oehler.de, the German shop, got Speed Kit and the other half, the control group, did not. The Speed Kit group reached a 3.47% higher user conversion rate and placed 3.02% more orders.
Performance Improvements — Largest Contentful Paint (LCP): On the accelerated pages in Austria, the main content reaches the customer 700 ms, or 49%, faster. Product pages gain 53%, category pages 41%, and the first byte arrives 75% sooner. In the Swiss shop the main content loads 46% faster, in the German shop 32%.
Conclusion
Kastner & Öhler wanted more speed for its shops and a clear answer to what it is worth. With Speed Kit, the main content on the accelerated pages in Austria loads 49% faster, and during the PoC phase the Speed Kit group in the German shop converted 3.47% better than the control group. After the PoC, Kastner & Öhler decided to continue with Speed Kit.
