Introducing a sticky Add to Cart bar increased engagement and conversion rates by keeping purchase options always visible. Read on to discover the impact.
Sticky Top Add to Cart Bar with Size Selector


If we introduce a top sticky Add to Cart bar with a size selector and preselection, then the add to cart rate will increase on PDPs, because users can complete the purchase flow faster without needing to scroll back up or select sizes manually.
What We Changed
- Introduced a top sticky Add to Cart bar on product pages.
- Added a size selector dropdown to the sticky bar.
- Enabled size preselection to keep the Add to Cart button active.
- Included a "Find my size" link for user guidance.
The Results
We dig through every data source to map what's actually broken. By the end, there's no confusion.
Click-through rate change
Change in amount of clicks
Lift in conversion rate
Key Learnings
- Constant visibility of purchase options reduced decision friction.
- Preselected sizes encouraged quicker add-to-cart actions.
- Improved engagement led to higher conversion and click-through rates.
- Reduced bounce rates by keeping users engaged on product pages.
Detailed results breakdown
Add-to-cart rate change
+2.2%
Average order value
-6.9%
Click-through rate change
+14.0%
Lift in conversion rate
+9.6%
Change in revenue per visitor
+2.3%
Start with 3 experiments.
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30,000+ Monthly sessions.
Minimum traffic needed to run statistically significant tests.
Running on Shopify or Shopify Plus.
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Investing in paid traffic.
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Ready to invest in systematic CRO.
You understand testing takes time - no magic bullets.
Why free?
The best proof is results. Three real experiments show you exactly how we work and whether it drives revenue for your specific store. You keep everything - no strings attached.
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