Checkout is one of the highest-impact stages of the customer journey. Small changes to messaging at this step can meaningfully improve checkout completion rate.
With Checkout Block Testing, Shopify Plus merchants can run A/B tests on checkout content using Shogun and Shopify’s Checkout Blocks app.
This feature lets you experiment with checkout messaging without modifying the checkout code.
Availability
This feature is available only if:
You are on Shopify Plus
You are on the Shogun A/B Testing Unlimited plan
You have installed Shopify’s Checkout Blocks app
Shopify restricts checkout customization to Plus merchants.
What You Can Test
You can test dynamic checkout content, such as:
FAQs
Shipping guarantees
Trust messaging
Subscription education
Financing messaging
Urgency messaging
Carbon offset messaging
You can add a new block, hide an existing block, or swap one block for another. You can also control the visibility of multiple blocks within a single variant.
How It Works
When a shopper is assigned to a Shogun variant, Shogun writes a cart attribute:
Key: shogun_variant_id
Value: A unique ID for the variant
The Checkout Blocks app uses a display rule that checks for this cart attribute.
If the key and value match, the block displays.
If they do not match, the default checkout experience appears.
No checkout layout code is modified.
Supported Block Types
Only Checkout Blocks that support Cart Attribute display rules can be tested:
Dynamic Content
Custom Field
Line Item Edit
Static blocks, line item content, and shipping or payment icons are not supported.
Setup Guide
Step 1: Create a Checkout Test in Shogun
Open Shogun A/B Testing and create a new Checkout Test.
After saving, Shogun generates:
Cart Attribute Key: shogun_variant_id
Cart Attribute Value: A unique value for your variant
Copy this value exactly. You will use it in the Checkout Blocks app.
Configure your traffic split, goal, and audience. Do not publish yet.
Step 2: Create a Checkout Block
In Shopify Admin:
Install the Checkout Blocks app if needed
Open the app
Create a new block
Select Dynamic Content, Custom Field, or Line Item Edit
Configure your content
Save
Step 3: Add the Display Rule
Inside your Checkout Block:
Add a Display Rule
Choose Cart Attributes
Enter the following
Key: shogun_variant_id
Value: Paste the value from your Shogun test
This ensures only shoppers assigned to that variant see the block.
Set the block to Active and save.
Step 4: Add the Block to Checkout
Go to Online Store → Customize in Shopify.
Navigate to Checkout.
Add an App Block and select your Checkout Block. Choose the correct Block ID and save.
You can use the preview feature inside Checkout Blocks to confirm how the block will render.
Step 5: Publish the Test
Return to Shogun.
Click Review, then Publish.
Your checkout test is now live.
Step 6: Validate
To confirm everything is working:
Open your store in an incognito window
Add a product to the cart
Proceed to checkout
Depending on variant assignment, you may see either the default checkout or your new block.
Variant assignment follows your configured traffic split.
Troubleshooting
If the block does not appear:
Confirm the block is Active
Confirm the display rule uses Cart Attributes
Confirm the key is exactly
shogun_variant_idConfirm the value matches your Shogun test exactly
Confirm the block is added to the Checkout editor
Confirm the test is published
If everyone sees the same version, check your traffic split and confirm the display rule value matches the variant ID.
Summary
Checkout Block Testing allows Shopify Plus merchants to experiment with checkout messaging using Shogun’s A/B testing engine and Shopify’s native Checkout Blocks infrastructure.
It does not modify the checkout layout, does not require developer work, and uses Shopify’s supported cart attribute display rules.
This feature is designed for merchants focused on optimizing checkout completion rates and reducing abandonment rates.