Checkout simulator

Updated · SMART Shipping Rates (E-TRADE PARTNER)

The Checkout simulator builds a test cart and destination, then runs them through the same calculated-rate pipeline Shopify uses at checkout. It does not evaluate Delivery customizations, so rates those rules would hide, rename, or reorder still appear unchanged.

4.9 · SMART Shipping Rates does this with zones, calculated rates, and delivery customizations.

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On this page
  1. What the simulator runs
  2. What it does not evaluate
  3. When simulator and checkout disagree
  4. Frequently asked questions

Use Checkout simulator before you go live with calculated rates. Confirm hide, rename, and sort rules later in real Shopify checkout, because those actions come from Delivery customizations.

What the simulator runs

You build a cart and a destination, then SMART runs that request through the real rate engine. The result is the calculated rates checkout would receive from this app, including Shipping rates and Combined rates when Shopify Carrier Service is available.

  1. Open Checkout simulator.
  2. Add the products, quantities, destination, and Ship from location you want to test.
  3. Click Run simulation and write down the expected calculated rates.
  4. Repeat with a cart or address that should not match.
  5. Confirm hide, rename, and sort rules in a real Shopify checkout.

What it does not evaluate

Checkout behaviorIn the simulator
Calculated SMART ratesEvaluated by the same rate pipeline as checkout
Delivery customizations that hide, rename, or reorder methodsNot evaluated. Those rates still appear unchanged
Items that do not require shippingCheckout skips them for rate requests. The simulator may still include them

Delivery customizations are not applied

The simulator shows calculated rates before Delivery customizations change the method list. A rate that should be hidden, renamed, or reordered at checkout can still appear here with its original name and order.

When simulator and checkout disagree

  • If calculated rates look wrong in the simulator, check zones, conditions, Settings, and Product dimensions first.
  • If calculated rates look right here but live checkout differs, open Activity log and compare the real carrier-service request.
  • If the price is right but the method name, visibility, or order is wrong, test Delivery customizations in real checkout.
  • Digital or non-shipping items can make simulator results differ from checkout, because checkout may omit them from the rate request.

For a broader test plan, read Test your setup. If a live calculated rate is missing, see Shipping rates not showing and Activity log. For a worked example, use the checkout simulator guide.

Test calculated rates before customers see them

Use SMART to simulate a cart and destination through the same calculated-rate engine as checkout, then confirm delivery customizations in real Shopify checkout.

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Frequently asked questions

Does the simulator apply delivery customizations?

No. The simulator does not evaluate Delivery customizations. Rates those rules would hide, rename, or reorder still appear unchanged.

Does the simulator use the same engine as checkout?

Yes. The Checkout simulator runs the test cart and destination through the same calculated-rate pipeline Shopify uses at checkout.

Why might simulator results differ from live checkout?

The simulator does not apply Delivery customizations, and it may still include items that do not require shipping. Checkout skips those items when it asks for rates.

What should I do if the simulator and live checkout disagree on calculated rates?

Use Activity log to inspect the real carrier-service request. Compare destination, cart, and matched outcome with the simulation you ran.

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