Srovname.cz: 25% More Mobile Conversions from Speed Improvements
Srovname.cz is a Czech price comparison site that helps users find the best deals across e-shops.
In 2016, we accelerated the mobile site Srovname.cz, resulting in a 25% increase in mobile conversion rates. These aren’t just numbers in reports; they translate to real money in the bank.
Website speed directly affects company revenue. It’s not just a technical enhancement; it’s a business necessity. A faster website leads to higher conversions, lower PPC costs, better SEO chances, and happier visitors.
Specific adjustments: surgical tweaks instead of a revolution
We broke down Srovname.cz into components and focused on low-hanging fruit, such as:
- Slimmer CSS: fewer files, higher speed
We combined all styles into one file and minimized it. Critical CSS (styles needed for the first screen) was embedded directly into the HTML code of the page. - Parallel processing with asynchronous JavaScript
The issue was that all JavaScript loaded sequentially, blocking content display. We switched to asynchronous loading, allowing important content to display immediately while less critical scripts load in the background. Users see the page right away, and interactive elements are fine-tuned later. - SVG graphics: Vector icons instead of pixel images
We converted main icons and components to SVG and embedded them directly into the HTML code. This way, the browser didn’t have to download dozens of small images separately.
Collaboration with the Srovname.cz team was excellent. Adjustments were smooth and real-time.
Measurable results: pages up to 80% faster
Optimization without measurement is just shooting in the dark. We primarily used WebPageTest.org and Speed Index metrics for measurement at that time.
Speed Index (SI) measures how quickly the page content gradually appeared to the user. The lower the number, the faster the loading. This metric was important in 2016, but it’s now outdated—we now use more modern loading speed indicators like Largest Contentful Paint (LCP).
How Did the Optimizations for Srovname.cz Turn Out?
| Page | Speed Index Before | Speed Index After | Improvement |
|---|---|---|---|
| Homepage | 6,664 ms | 1,340 ms | 80% faster |
| Product List | 3,654 ms | 2,275 ms | 38% faster |
| Product Detail | 4,001 ms | 1,506 ms | 62% faster |
Content on mobile now displays in under 1.5 seconds instead of the previous six seconds. That’s a difference users notice at first glance.
Synthetic metrics showed dramatic improvement. But what did the users say?
Conversions: Where True Value Shows
The conversion rate on Srovname.cz indicates how many users click through from the comparison site to the e-shop detail. How did it change after optimization?
| Device | Change in conversion rate |
|---|---|
| Desktop | +1.3 % |
| Tablet | +4.5 % |
| Mobile | +24.8 % |
We achieved a nearly 25% increase in conversion rate on mobile, which is fantastic.
Data source: Google Analytics. Compared periods: April 14, 2016 – April 13, 2017 vs. the same period a year earlier. Measured on traffic in the hundreds of thousands. For mobile, this means tens of thousands of visits.
In the case of Srovname.cz, we had the advantage that minimal other changes were made to the site during that time, so the impact of speed is visible in its purest form.
What’s next? Optimization is not a one-time action
Website speed is not a goal to achieve once and then forget. With every website's development, speed tends to deteriorate over time.
Speed should be part of your business processes; otherwise, you’re wasting money.
The team at PageSpeed.cz can assist you with automated monitoring, expert oversight, training, or high-level services like assessing the impact of speed on business.
Optimization of Srovname.cz demonstrated that website speed is not just a technical gimmick but a business advantage. Especially on mobile, faster websites equal more revenue.
Note: The optimization of Srovname.cz in 2016 was conducted by Martin Michálek, who now leads the PageSpeed.cz team. You can find the original article at Vzhůru dolů.