URL Parameters Reference

Dynamic links allow you to personalize checkout experiences by passing URL parameters. Toggle on Dynamic to enable parameter processing for your link.

Line Items ?li=

Add products to the cart with optional selling plan and line item attributes.

?li=variantId,quantity,sellingPlanId,[key,value:key,value]

Customer ID ?c=

Pre-fill checkout with a customer's saved details using their Shopify customer ID or Klaviyo profile ID.

?c=customerId

The customer's saved name, email, and shipping address are pre-filled at checkout. Klaviyo profile IDs require the Klaviyo integration to be configured.

Inline Customer Data ?c=

Pre-fill checkout with customer data passed directly in the URL.

?c=[key,value:key,value]

Available fields:

Cart Attributes ?attr=

Add custom attributes to the cart.

?attr=[key,value:key,value]

Cart Note ?note=

Add a note to the order.

?note=URL encoded text

Abandonment ?a=

Restore an abandoned cart using a Shopify abandonment ID.

?a=abandonmentId

This parameter is used with abandonment recovery integrations. The abandonment ID is provided by Shopify's abandoned checkout data.

Reorder Items

When Dynamic is enabled, a Reorder items checkbox appears in the Cart card. When checked, the link will automatically add items from the customer's previous order.

How it works:

1. Enable Dynamic mode on your link
2. Check "Reorder items" in the Cart card
3. Pass a customer ID via ?c= parameter in the URL
4. The customer's most recent order items are automatically added to cart

Example URL:

https://yourstore.com/go/reorder?c=7654321098765

This is the recommended approach for email campaigns and retention flows.

Combining Parameters

You can combine multiple parameters in a single URL:

https://yourstore.com/link?li=12345,1&c=7654321098765&attr=[Gift,true]&note=Please%20gift%20wrap

Promotions & Security

How promotions work with dynamic links

Promotions are configured on the link itself, not in the URL. This means:

• Customers get the discount you configured
• Bad actors can't change or guess discount codes
• Your promotion rules always apply
• Line item discounts in URLs are ignored on dynamic links

Recommended: Use tiered promotions with caps

For dynamic links, we recommend setting a maximum discount value:

Tier 1: 10% off for carts $0-50
Tier 2: 15% off for carts $50-100
Maximum discount: $100

This limits exposure if someone adds unexpected items to the cart.

Need product-level restrictions?

If you need discounts to only apply to specific products:

1. Create a discount code in Shopify with product/collection restrictions
2. Add that discount code to your link in the Checkout Links UI
3. Shopify enforces the restrictions automatically

Important Notes

Dynamic mode must be enabled

URL parameters are ignored unless you enable Dynamic Mode on the link. This is a security feature.

URL length limits

Most browsers support URLs up to 2,000 characters. For QR codes, keep URLs under 500 characters for easy scanning.

Tips for shorter URLs:

• Use ?c= with a Shopify Customer ID instead of full address fields
• Create customers in Shopify first for returning buyers
• Keep cart attribute keys short

Analytics

Dynamic links track analytics the same as regular links. All clicks and orders roll up to the link you created.

Want granular tracking? Create separate links:

• summer-campaign-email for email sends
• summer-campaign-social for social posts
• summer-campaign-sms for SMS

Each tracks separately, all can use dynamic parameters.