Introducing: Cross-Site Testing

Cross-Site Testing allows you to run true end-to-end A/B tests by comparing entire Shopify themes and their connected checkout experiences. Instead of optimizing isolated elements, you test complete customer journeys.

January 25, 2026

What Cross-Site Testing Is

Cross-Site Testing lets you A/B test entire Shopify themes against each other.

Traffic is split at the storefront level. For example:

• 50% of shoppers see Theme A
• 50% of shoppers see Theme B

Each theme can be connected to its own checkout experience inside PDQ.

This is not page-level testing. This is full experience testing.

Why Cross-Site Testing Exists

Most A/B testing tools optimize fragments. A button. A banner. A headline.

Shoppers do not experience fragments. They experience a flow:

Land on site. Browse. Add to cart. Checkout. Purchase.

When the storefront promise and the checkout reality do not match, trust breaks.

Example failure:

• Theme promotes Free Shipping
• Checkout shows $9.99 shipping

The shopper feels misled. Conversion drops.

Cross-Site Testing removes this disconnect.

What Makes Cross-Site Testing Different

Cross-Site Testing allows you to pair each theme with a matching checkout experience.

Example:

Each shopper sees a consistent story from first page to payment confirmation.

This unlocks tests that were previously impossible:

• Free shipping themes vs standard pricing themes
• Premium brand redesigns vs legacy layouts
• Aggressive promos vs margin-protected experiences

You are no longer testing components. You are testing business strategies.