What exactly is an A/B test?

A/B testing is a tool that turns hypotheses into data-driven decisions: instead of relying on intuition, it measures the real impact of changes on user behavior.

The mechanism compares the current version of an element (A) with a new variation (B) to determine which one better encourages users to take the desired action, such as making a purchase or signing up.

Statistical analysis of the results objectively determines which version impacts — and how — the most important KPIs for e-commerce, such as Conversion Rate (CR), Average Order Value (AOV), or Click-Through Rate (CTR), allowing continuous performance optimization.

7 practical A/B tests for your c-commerce

1. 1. Homepage

The homepage is often the first touchpoint for new users; testing can help you understand whether your audience is looking for inspiration or wants to shop quickly.

Test: Focus on Brand Storytelling vs. Focus on Product

The hypothesis is that a product-focused approach, showcasing a selection of items, will generate higher CTR and Conversion Rate compared to a layout that gives more space to brand storytelling.

KPIs to measure

• Primary KPI: 
  • Click-Through Rate (CTR) cross homepage sections
• Secondary KPI:
  • Conversion Rate (CR) of homepage visitors
  • Bounce Rate
  • Scroll depth

A test on this topic revealed that blog articles linked on the homepage in the variant saw a +196% increase in traffic compared to the control version (which linked to a PLP instead), suggesting greater user engagement with brand-focused content.

2. Category Page (PLP)

The Product Listing Page (PLP) should make product discovery easy. One element to test is the usefulness of navigation links (cross-links) to related categories to improve user exploration.

Test: Visibility of Cross-Links Between Related Categories

The hypothesis is that well-placed and visible links to related subcategories increase catalog exploration and, consequently, the Conversion Rate.

KPIs to measure

• Primary KPI:
  • Click-Through Rate (CTR) on cross-link

• Secondary KPI:
  • Traffic on the tested PLPs
  • Conversion Rate (CR)

Clearer navigation on PLPs can have a major, twofold impact. On average, our tests improved catalog exploration by +20% in cross-link interactions and +15% in traffic on tested PLPs. These results translated into an average +15% increase in final Conversion Rate.

3. 3. Filters & Sorting

In a catalog with many products, filters and sorting tools are essential to guide users toward the right choice. Their effectiveness largely depends on visibility and ease of use, especially on mobile.

Test: Visibility and Placement of Filters and Sorting Options

The hypothesis is that making filter and sorting buttons more prominent and always accessible (e.g., via a sticky bar positioned at the top or bottom) increases their use and improves navigation efficiency.

KPIs to measure

• Primary KPI:
  • Filter interaction rate (filter clicks / sessions)

• Secondary KPI:
  • Conversion Rate (CR)

Making filter and sorting controls more visible had a strong impact on usage: our tests recorded up to a +90% increase in filter use, resulting in an overall +8% lift in Conversion Rate.

4. 4. Product Detail Page (PDP)

The Product Detail Page (PDP) is the heart of any e-commerce; it’s where users make the final decision to add an item to their cart, and every element should be optimized for conversion.

Test: Position of the “Add to Cart” CTA

The hypothesis is that placing the “Add to Cart” CTA in an immediately visible position (“above the fold”) increases add-to-cart rates.

KPI to measure

• Primary KPI: 
  • Add-to-Cart Rate (CTA clicks / sessions)

• Secondary KPIs:
  • Final Conversion Rate (CR)

Our data confirms the importance of this test. On average, a more effective CTA placement generated a +20% increase in add-to-cart clicks, with a positive impact of +7% on the final Conversion Rate.

5. 5. Cart Page

The cart page is the final step before the actual checkout. The goal here is to reassure the user and make the next action as clear and inviting as possible, eliminating any hesitation.

Test: Visibility of the Main CTA to Checkout

The hypothesis is that improving the page’s visual hierarchy — by placing the “Go to Checkout” CTA prominently above the fold and reducing surrounding distractions — increases its effectiveness and encourages more users to proceed to checkout.

KPIs to measure

• Primary KPI: 
  • Click-Through Rate (CTR) on the checkout button

• Secondary KPIs:
  • Conversion Rate (CR)

Increasing the visibility of the checkout button represents an intervention with potentially very positive impact. Our tests recorded an increase in CTR toward checkout of up to +18%.

6. Checkout

The checkout is the final and most delicate stage of the funnel, where any friction can cause abandonment. A key test concerns its structure: is it better to use a single page or multiple separate steps?

Test: One-Page Checkout vs. Multi-Step Checkout

This test compares two types of checkout: the speed of a single-page checkout (One-Page) versus the clarity of a guided, multi-step path (Multi-Step), to determine which approach maximizes conversion rate and reduces abandonment at this crucial stage.

KPIs to measure

• Primary KPI: 
  • Checkout Completion Rate (orders / sessions that start checkout)

• Secondary KPI:
  • Step abandonment rate (for Multi-Step version)
  • Conversion Rate (CR)

Our data shows that for premium or complex products, adopting a multi-step checkout structure can lead to a Conversion Rate increase between +5% and +7%.

7. On-Site Search

The search bar is a crucial tool for users with high purchase intent. Making it as immediate and accessible as possible on mobile devices can have a direct impact on sales.

Test: Always-Visible Search Bar vs. Standard Search

The hypothesis is that a search bar that remains visible and accessible while scrolling (“sticky”) on mobile encourages greater use of the search function, leading to a higher conversion rate among these users.

KPIs to measure

• Primary KPI: 
  • Percentage of sessions with at least one search

• Secondary KPI:
  • Conversion Rate of sessions using the search function

Improving search bar visibility has a concrete impact. On average, our tests showed an increase of over +30% in sessions using search, which translated into an average +18% increase in Conversion Rate.

These are some of the most effective A/B tests to start with, but a true optimization program requires a strategic and ongoing approach. Thanks to our expertise in UX and Data Analytics, we can help you build a structured testing process to analyze your funnel and identify the highest-impact, data-driven opportunities.