Before you launch or pay for traffic
Shop checkout checklist: rules that stop orders
Most checkout errors appear a few screens after the buyer made their choice, not on the screen where the rule was written. A simulated visitor can run the path as a buyer and show the step where the rule fires.
What belongs on a shop checkout checklist?
A shop checkout checklist covers the rules that can stop an order: shipping destinations, tax, discount codes, stock and the total at payment, plus the record and the email an order leaves behind. Most of those rules are checked at one specific step, so the error appears there and not on the first screen. A simulated test sends a visitor through the cart and checkout up to payment, and shows where each one stopped and what the screen said.
What this looks like in a report
“The candles were on the home page, so why did it let me type my address? Now it says the shop does not deliver here. Should I give up or try a different address?”
The fix. Check the shipping destinations at the address step against the list you publish, and show the unsupported countries on the product page before the cart. Name the country in the message, and offer a contact link for a special order.
An illustration. Run a test to see your own.See a real sample report
Each step passes, and the rule that stops the order sits at the end
A checkout is a set of small rules, and each one is checked where it was written. Shipping is checked when the address is saved, tax when the total appears and stock often when the order is placed. A buyer can pass three screens before the rule that matters catches them, and the error arrives after they have typed an address and a card. You never see this on your own cart, which already passes. A new buyer, with a different country or a code you forgot to expire, meets the rule you never tested.
- Every country you ship to is listed, and an unlisted one gets a clear message at the address step.
- A discount code applies once, shows its amount, and rejects an expired code in words a buyer understands.
- Stock is checked again at the last step before payment, not only on the product page.
- The total at payment equals the cart plus shipping and tax, with each line named.
- A real order leaves an order record, a confirmation email and a stock change you can find.
Shipping, tax and minimums are checked at the wrong time
Many checkout errors show up on a later screen than the one that caused them. Shipping destinations are checked when the address is saved, a minimum order is checked when the total is calculated, and a discount code is checked only when it is applied. The error then arrives on a step the buyer believed was finished. A buyer who sees the address accepted and a total on screen expects the order to go through. The tell is the step count: if the error appears after an address and a total are on screen, the rule sits in an earlier step.
Check each rule where it fires. List every country you ship to, then run a buyer to an unlisted one and read the message. Apply a code that has expired and read that message too. Put a cart under your minimum and watch when the block appears. A message that appears only at payment is a rule placed too late, so move it back to the cart.
What a visitor run covers, and what it leaves out
A simulated visitor can add items, enter a guest address, choose a shipping option and reach the payment step. It can show the total the visitor reads at that step, whether a discount code applies, and whether an unsupported country is refused, with the message on screen. It stops at the payment step. It cannot pay with a real card, so a declined card, a bank's verification prompt or a failed charge sits outside the run, and you check those yourself.
Keep the run on the first-time buyer's path. Use a guest address that is new to the shop. A signed-in account with a saved address skips the step that often fails, so a run through a saved account tells you less. Simulated visitors cannot sign in with Google or single sign on, so the guest path is the path they run anyway.
Your own order is the step only you can finish
Once the run is clean, place one real order yourself, with a card you own and an address you control, then refund it. Read the order record in your admin, the confirmation email and the invoice, and check that stock went down by one. Compare the tax and shipping on the invoice with your own rates. A simulated visitor cannot tell you any of that, and a clean run is no proof that the order record exists.
Four ways to check a checkout, and what each one misses
| Method | What it shows you | What it cannot show you |
|---|---|---|
| A simulated visitor | Where a first-time buyer stops, the message on screen and a screenshot | Whether a charge succeeds or an order record is created |
| Your own test order | Whether a real card goes through, the order record and the email | How a stranger reads the page, because you already know the shop |
| A scripted end to end test | Whether a known path keeps passing after each release | Confusion on a step nobody wrote a script for |
| Your analytics | Where buyers leave in total, once real traffic arrives | Why one buyer left, or what they expected to find |
Run the first two before orders, and the last two after.
What you get with Mimiq
- 01
Run it by hand, or on every pull request
Paste a link and a task in the app and watch the visitors work. Or run them on every preview deploy: the GitHub Action comments on the pull request, any other CI can call the MCP endpoint, and your coding agent can run it too.
- 02
Bugs and usability problems in one report
The browser records errors and failed or slow requests on the step they happened. The visitors say where the wording or the steps confused them, and where they left.
- 03
Visitors that behave like your audience
Each visitor is a different profile with a reason to be there, matched to who the page is for, described by you, or built from your own customers.
- 04
A prompt to fix each problem
Every problem comes with a fix to paste into Cursor, Claude Code, Lovable or any coding agent, and one prompt hands over the top problems at once. Then send the same visitors through again.
- 05
Follow every visitor
See each visitor's whole path, step by step with screenshots, and what it was thinking at every step. Ask any visitor a question.
The browser records relevant JavaScript errors and failed or slow app requests encountered during the run, attached to the step where they occurred. The visitors are simulated: they find problems, they do not predict how many real people will convert.
A new shipping zone or a tax change can reopen a checkout error
Shipping zones, tax rates and discount codes change with each season and each new product. A change can move a rule to a later step than before, where the last test never looked. Rerun the same first-time buyers after every change to a rule, on a preview address, and check the payment step each time.
Starter
Try it on one launch
About 4 tests of 5 visitors
- Visitors on your landing page, signup and checkout
- Where they left and why, with a fix to copy for each problem
- Run it in the app or on every pull request
- Ask any visitor a question, included
- Test accounts and protected previews
Builder
Test every build
About 20 tests of 5 visitors
- Everything in Starter
- Credits refill each month, and what is left rolls over once
- Cancel anytime
Pro
Test every release, as a team
About 60 tests of 5 visitors
- Everything in Starter
- Credits refill each month, and what is left rolls over once
- Cancel anytime
Scale
Test at scale, every day
About 240 tests of 5 visitors
- Everything in Starter
- Credits refill each month, and what is left rolls over once
- Priority support
- Cancel anytime
Questions
Can I skip the real order if the test passes?
No. A passing run shows that a visitor reached the payment step with the right total. It does not show that a charge goes through, that an order record exists or that the confirmation reaches the buyer. Place one real order and refund it before you take traffic.
Should the checklist cover tax in every country?
Cover the countries you sell into. A simulated visitor can show whether an unlisted country is refused clearly. It cannot tell you whether your tax rate is right for that country, so check that with your accountant or tax provider.
What if a discount code works in the test but not for buyers?
Compare the code's rules with a real buyer's cart. A code can carry a minimum order or a single country, and a visitor with a small cart never meets the minimum. Run the code once with a cart that matches a real buyer's, then read the message it gives.
Does the test show my checkout conversion?
No. It does not predict how many buyers finish checkout, and it gives no rate. It shows the step where each simulated visitor stopped and the message on the screen. Rates come from your analytics once real buyers arrive.
Keep reading
Send visitors and see what breaks first.
Your first test is free: sign in with Google and it starts right away. Last checked 2026-11-02.