mufatechSTUDIO Install ↗

STORE DIAGNOSIS / FREE SHOPIFY APP

Live on the Shopify App Store · Free

Where your store’s money is stuck.

Store Diagnosis reads your products, stock and orders and tells you which products are tying up cash, which best-sellers will run out before a reorder lands, and which discounts cost more margin than they bring in. Each finding comes with the amount at stake, the arithmetic behind it and the steps to fix it yourself.

Install from the Shopify App Store See what it finds ↓

Listed as Mufatech Store Diagnosis. Approve four read permissions and your first report arrives within a minute or two.

Free No plans, no trial, no billing
Read-only Cannot change your store
No customer PII No names, emails or addresses
Gone when you leave All store data erased 48 h after uninstall
The Store Diagnosis overview inside the Shopify admin: a store health score ring, figures for net sales, what is kept after costs, money in stock, sales at risk and margin leaking, quick wins for the week, and an action plan ranked by money for each minute of work.
  • Dead stock Demo store
    $4,400.00 tied up

    Leather Tote. 40 units on hand and nothing sold for about nine months.

  • Stock-out Demo store
    Out before a reorder lands

    Reed Diffuser, Cedar. Under three weeks of stock left, and a reorder takes 21 days.

  • Action plan Every store
    Ranked by money per minute

    Each fix shows what it is worth, the minutes it takes and the arithmetic behind it.

The overview inside the Shopify admin, on our demo store. The notes around it come from the same store’s findings: diagnosis-d9qyllsk.myshopify.com, a development store we generated to test the app, so none of these figures belong to a real merchant.

HOW IT READS YOUR STORE

From your store
to a ranked list.

One read of your products, stock and orders. Five checks put a price on every problem, rank the problems by money for each minute of work, and tell you what to do.

  1. 1 · Your store

    Products, stock and orders

    • Prices and cost per item
    • Stock at every location, and stock on its way
    • Orders with discounts and refunds
  2. 2 · Read-only access

    Four read permissions

    • read_products
    • read_inventory
    • read_locations
    • read_orders

    No write access. No customer details.

  3. 3 · Five checks

    Where money is stuck or leaking

    • Dead and slow stock
    • Stock-outs
    • Margin leaks
    • Profit by product
    • ABC classes
  4. 4 · Ranked

    Findings, priced and ranked

    1. $12,920.0010 minMark down
    2. $323.2715 minReorder
    3. $104.42*5 minFix discount

    Money for each minute of work decides the order.

  5. 5 · Your admin

    Fix steps you follow

    Each finding lists the steps in your Shopify admin, in order. The app changes nothing.

    Mark a fix as started. When a later run no longer finds the problem, it moves to Resolved and counts towards what your fixes recovered.

  6. 6 · Mondays

    Weekly email

    The three findings with the most money attached, and the first step for each. Optional, and off in one click.

Step 4 shows one finding from each check in the accuracy test run of our demo store, in the order the action plan ranks them. * Estimated: some products on that code have no cost price set.

WHAT IT FINDS

Four questions,
answered in money.

Shopify’s reports show you numbers. Store Diagnosis decides which of them is a problem, puts an amount on it and ranks every problem by what it costs you. The charts come from the accuracy test: the app’s checks run on our demo store’s full year of orders. The screenshots show the live app on the same store, so their totals can differ.

Stock not selling

Which products are tying up cash?

Stock that has stopped selling, valued at what you paid for it.

  • Stale: no sale for 90 days. Dead: none for 180 days.
  • Never sold: in stock for 90 days or more without a single sale.
  • Slow: more than 180 days of supply at the current pace.
  • Seasonal: with a full year of orders, stock that sold strongly in the coming months last year is held back until its season has passed, and the report says how many.
  • A markdown that never prices below cost plus 5%, or a bundle or clearance when the margin allows no discount.
Capital tied up = units on hand × cost per itemVariants stocked for less than 30 days are not judged yet.

Money in stock at cost, by how it sells

Demo store · test run
Dead no sale for 180+ days$77,440
Stale no sale for 90+ days$10,673
Slow 180+ days of supply$43,631
Other stock selling, seasonal or new$242,539

$374,283 in stock at cost across 351 stocked variants. $88,113 of it, 24%, is dead or stale. 64 variants that sold strongly in the coming months last year, mostly winter ranges, were held back as seasonal instead of being reported in September.

The Store Diagnosis findings list, filtered by status and area: each finding with a one-line summary, its area, severity, the date first seen and the money at stake.
The findings list, filtered by status and by area.
Best-sellers running out

What sells out before the next delivery?

Products selling fast enough that running out would cost real sales.

  • Selling pace from the last 30 days (weighted 60%) and the last 90 days (40%).
  • Days of stock left, counting stock already on a purchase order or transfer.
  • A reorder quantity that covers a 21-day lead time and 45 days of selling after it.
  • A slower size is judged once it has sold at least twice in 90 days and running out would cost at least $50.
Revenue at risk = days short of the lead time × units a day × priceThe sales you would miss between running out and a reorder landing.

Reed Diffuser, Cedar: stock left against the wait for a reorder

Demo store · test run
Today
12 on hand Day 14
runs out Day 21
reorder lands Day 66
45 days covered
Stock on handNo stock: sales missedCovered by a reorder of 44

12 on hand at about 5.9 a week runs out in 14 days. A reorder takes 21 days to land, so about 7 days of sales are missed: $323.27. Ordering 44 today covers the 21-day wait and 45 days of selling after it, less the 12 on hand.

A stock-out finding in Store Diagnosis: revenue at risk, units on hand, the selling pace and days of stock left, the arithmetic behind them, and a reorder box with the number of units to order and the steps to place the order.
A stock-out finding in the app, with its reorder box and steps.
Margin leaks

Which discounts and orders lose money?

Margin that leaks out every week without anything looking broken.

  • Discount codes whose orders keep less than 15% after product cost and payment fees.
  • Products sold below cost once the discount is applied.
  • Two or more codes on one order taking off more than 40%.
  • Refunds above 8% of revenue, and orders so small the fixed payment fee takes more than 8% of them.
Leak = what it takes to bring each code back to a 15% marginPayment fees are counted at 2.9% + 30¢ an order. A leak is listed once $50 or more is at stake.

Margin kept after product cost and fees, by discount code

Demo store · test run
WELCOME1055%
SUMMER2051%
VIP2544%
BFCM3040%
BLACKFRIDAY50 listed: $104.428%
VIP40 $35 at stake−74%
15% margin floorBelow the floor, listedBelow, under $50 at stake

BLACKFRIDAY50 kept 7.7% on its 15 orders. Bringing it up to 15% would take $104.42, marked as estimated because some of its products have no cost price. VIP40 sits further below the floor, but on 6 orders only $35 is at stake, under the $50 a leak needs to be listed.

Where each sale goes, over the year

Demo store · test run

Gross sales $1,117,097, less $38,865 in discounts and $36,859 in refunds, is $1,041,373 in net sales. Less $427,947 of product cost and $33,248 of payment fees, the store keeps $580,179: 56% of net sales. Shipping charged to customers ($18,865), ads and overheads are left out.

Profit by product

Which products carry the store?

What each product keeps, and where the money in stock sits.

  • Every product’s net sales, discounts, refunds, product cost, payment fees and what is left.
  • ABC classes: the products that bring 80% of sales, the next 15%, and the long tail.
  • How much of the money in stock sits in the long tail.
  • Sales and what you keep, month by month.
Kept = net sales − refunds − product cost − payment feesShipping costs, ad spend and overheads are not visible to the app and are left out.

Share of sales, products ranked from the best seller down

Demo store · test run
Cumulative share of sales across 83 products The curve rises steeply: the 38 best-selling products bring 81% of sales, the next 20 bring the total to 95%, and the last 25 bring the remaining 5%. 0%20%40%60%80%100% 020406083 Products, best-selling first ABC 38 products bring 81% of sales
A · carry the store 81% of sales 38 products, holding 78% of the money in stock
B · steady 15% of sales 20 products, holding 12% of the money in stock
C · long tail 5% of sales 26 products, one of them unsold, holding 10% of the money in stock

83 products sold over the year. The ABC classes matched the known answer on all 83.

Profit by product in Store Diagnosis: figures for products sold, kept after costs, products losing money and stock in the long tail, then a table of each product with its A, B or C class, units, net sales, amount given away, cost and fees, what it kept, margin and stock.
Profit by product, with a filter for the products losing money.

Each area has a guide that explains the method and how to do it by hand: dead stock, reorder points, discount profitability, profit by product and ABC analysis.

ONE FINDING, FULLY EXPLAINED

No number you
cannot check.

Every finding opens as a piece of work: what was found, how the figure was worked out, what it assumes, and what to do about it in your own admin.

A stock-not-selling finding in Store Diagnosis. The main column shows what was found as evidence tiles, how the figure was worked out and what it assumes, then the fix with a table of what each markdown would leave and the steps. The side column shows the impact, the time to fix by hand, the product and a timeline.

  1. What we found

    The evidence: capital tied up, units on hand, days since the last sale and sell-through over 90 days. For a leak, the orders and the discount behind it.

  2. How we worked it out

    The arithmetic in sentences, such as “76 units on hand × $170.00 cost each = $12,920.00 of cash sitting on the shelf”, and what it assumes, in words.

  3. Fix it yourself

    The steps in your Shopify admin, in order. Where a markdown is justified, a suggested price that stays above your cost; where it is not, stop reordering and watch it. For a best-seller running low, a reorder quantity.

  4. What each markdown leaves you

    The new price, what you keep per unit and the cash if all sell, for each markdown. A row that sells below cost is marked.

  5. Impact and time to fix

    The money at stake, how serious it is, and a rough time to fix by hand, from 2 minutes to half an hour, so quick wins rank above long jobs worth the same.

  6. I’m fixing this

    Mark the finding as in progress. The next run checks whether it is gone, and if it is, it moves to Resolved.

What each markdown leaves you, for a finding from the demo store’s test run: Limited Edition Coach Jacket, XL, no sale for 203 days. Price $340.00, cost $170.00, 76 on hand
MarkdownNew priceKept per unitIf all 76 sell
None$340.00$159.84$25,840.00
10%$306.00$126.83$23,256.00
20%$272.00$93.81$20,672.00
30%$238.00$60.80$18,088.00
40% Suggested$204.00$27.78$15,504.00
50% Below cost$170.00−$5.23$12,920.00

Kept per unit is the new price less the 2.9% + 30¢ payment fee and the cost. Any markdown up to 48% still covers cost and fees here: 1 − ($170.00 + $0.30) ÷ ($340.00 × 0.971). Cash if all sell is before fees; it is what a clearance can turn back into money. The table makes no guess at how much faster the product would sell, because that is the one number you could not check.

ACCURACY

Tested on a store
with known answers.

We generated a Shopify development store with a year of orders from a fixed seed, so every problem in it is known before the app looks. Then we ran the checks and counted what they found, missed and flagged wrongly.

100%

precision on dead and slow stock

64 of 64 detected cases were real. No false alarms among 160 healthy variants.

94%

of known dead and slow stock detected

64 of 68 cases, before the 50-finding list limit. 44 of them in the list a merchant sees.

67%

of known stock-outs found

6 of 9 cases. 6 of 8 alerts were right.

2.5%

error on the store’s contribution after costs

$580,179 against $594,838, from unit costs the store left empty. Sales, discounts, refunds and fees match to the cent.

The test page gives every miss with its cause, the labelling rules and the command that reproduces the run.

Read the accuracy test

LANGUAGES

Written in 14 languages.

The app follows the language your Shopify admin is set to. The weekly email comes in the same languages, with amounts in your store’s currency.

  • English
  • GermanDeutsch
  • FrenchFrançais
  • SpanishEspañol
  • ItalianItaliano
  • DutchNederlands
  • Portuguese (Brazil)Português
  • Japanese日本語
  • Chinese (Simplified)简体中文
  • Chinese (Traditional)繁體中文
  • Korean한국어
  • SwedishSvenska
  • DanishDansk
  • PolishPolski
The Store Diagnosis overview with the Shopify admin set to German: the same health score, figures and action plan, in German.
The overview in German.
The Store Diagnosis overview with the Shopify admin set to Japanese: the same health score, figures and action plan, in Japanese.
The overview in Japanese.

PERMISSIONS AND PRIVACY

Reads four things.
Changes nothing.

The app asks for read access only, and never for customer details. Read-only is a permanent decision, not a setting.

What it asks Shopify for

  • read_productsProducts, variants, prices and cost per item.
  • read_inventoryStock levels, including stock on its way.
  • read_locationsWhich locations hold the stock.
  • read_ordersOrders with their lines, discounts and refunds.

No write permission of any kind. The app cannot change a price, a product, a discount or an order; every fix is something you do.

What it never does

  • Reads or stores a customer’s name, email, postal address or phone number. It does not read who placed an order at all.
  • Tracks whether you open its emails or click their links. There is no pixel and no rewritten link.
  • Keeps your store’s data after you leave: it is erased when Shopify asks, 48 hours after uninstall.

The app’s database runs on Mufatech’s own server with Hetzner in Germany, under EU data protection law (GDPR). Daily backups go to Cloudflare R2 and emails through Postmark. Details in the privacy policy, the terms and the data processing addendum.

SHOPIFY’S REPORTS AND STORE DIAGNOSIS

What your reports show,
and what they leave to you.

Shopify’s own reports are the right starting point, and the guides below use them. This is what each one gives you, next to what the app adds.

QuestionShopify’s own reportsStore Diagnosis
Which stock stopped selling? Products by sell-through rate over the most recent 30 days, Inventory remaining per product and Month-end inventory value. Products that sold nothing are not listed; you match an inventory export against sales yourself.1 Every stocked variant checked for days since its last sale, never sold and days of supply, valued at cost, with a markdown that stays above cost.
What runs out before a reorder? Inventory sold daily by product and Inventory remaining per product.1 Stocky is no longer available after 31 August 2026; Shopify points to purchase orders and low-stock alerts built with Shopify Flow.2 Days of stock left against a 21-day lead time, the sales missed before a reorder lands, and how many units to order.
Which discounts lose money? Sales by discount codes gives each code’s sales.3 Product cost and payment fees are yours to add. Each code’s margin after product cost and payment fees, flagged under 15%, with the amount it would take to reach 15%. Also stacked codes, sales below cost, refunds and small-order fees.
What does each product keep? Gross profit by product and by variant: net sales less cost. Sales without a cost recorded at the time are left out.4 Net sales, discounts, refunds, product cost, payment fees and what is kept, per product. Missing costs are estimated at a 50% margin and marked.
Which products carry the store? ABC product analysis grades variants on the last 28 days of revenue at retail price, and the window cannot be changed.5 A, B and C over the whole period the report covers, with unsold stock in C, and how much of the money in stock sits in the long tail.
What should I fix first? The reports show figures. Which of them is a problem, and what it costs you, is left to you. Every problem priced in money and ranked by money for each minute of work, with the steps to fix it.
  1. Shopify Help Center, Inventory reports.
  2. Shopify Help Center, Migrating from Stocky to Shopify inventory management.
  3. Shopify Help Center, Sales reports.
  4. Shopify Help Center, Profit reports.
  5. Shopify Help Center, ABC inventory analysis. Checked 25 September 2026; report names as quoted there. Shopify renames and moves reports from time to time.

HOW IT WORKS

Install once.
It keeps up.

No spreadsheets to connect and nothing to configure. The report stays current as your store changes.

  1. Install Once

    Approve the four read permissions from the Shopify App Store. No account to create.

  2. First read A minute or two

    Products, stock and orders are read in bulk. Most stores see their first report within a minute or two.

  3. Live changes Seconds

    Product, stock, order and refund changes reach the report within seconds through Shopify webhooks.

  4. Nightly run Every night

    Every finding is recalculated. Fixed problems move to Resolved on their own. You can also run the diagnosis again at any time.

  5. Weekly email Mondays

    The three findings with the most money attached and the first step for each. Turn it off in one click.

The weekly Store Diagnosis email: the total tied up or leaking, then the three largest findings, a leather tote not selling, a camp mug about to run out and a discount code losing money, each with what to do, and a button to open the full report.
The weekly email as the app’s own template renders it, from the sample report its tests use. The store name and figures are a sample.

WHAT IT DOES NOT DO

Plain about
the limits.

So you know which figures to firm up and where your own judgement still decides.

01

Missing costs are estimated

Where a variant has no cost per item in Shopify, the app assumes a 50% gross margin and marks every figure that depends on it as estimated.

02

One lead time for now

Stock risk is measured against a 21-day supplier lead time. If yours is longer, more of your range is at risk than the report shows, and it says so.

03

No shipping, ads or overheads

The app sees what customers paid for shipping, not what shipping cost you, and it cannot see ad spend or rent. Profit here is after product cost, discounts, refunds and payment fees.

04

60 days of orders to start

Shopify limits apps to the last 60 days of orders until it approves access to older ones, which we are requesting. The report states the period it covers, and the seasonal rule waits for a full year of orders.

05

Tested against known answers

On a demo store whose problems are known in advance, every dead-stock finding was real and 94% of the cases were found; stock-outs were found 6 times out of 9. Read the accuracy test, misses included.

GUIDES

Do it by hand
with these guides.

The same methods the app uses, written out step by step for Shopify admin, with the formulas and the pitfalls.

Shopify dead stock Find slow-moving inventory, value it at cost and set a markdown that stays above cost. Reorder points and stockouts Days of stock left, reorder point and quantity, now that Stocky is gone. Stocky alternative What replaces each Stocky job, free and paid. Discount profitability What a discount costs after fees, and how many more sales it needs. Profit by product What each product keeps after discounts, refunds, cost and fees. ABC analysis Find the few products that carry your sales, and the stock that does not. Shopify fees calculator What each plan really costs, card fees included.

QUESTIONS

Before you install.

Something else on your mind? Write to [email protected]

How do I install Store Diagnosis?

Open Mufatech Store Diagnosis on the Shopify App Store and click Install. Shopify shows the four read permissions it asks for; approve them and the first report arrives within a minute or two. There is no account to create and nothing to pay.

Is it really free?

Yes. The app has no plans, no trial and no billing. Every finding comes with the steps to fix it yourself in your Shopify admin, at no cost.

Can I see something before I install?

Yes. The free store audit reads the catalogue your store already publishes and shows how much of it is sold out or permanently on sale and what is missing, scored against the most-visited Shopify stores. It works on any store's address, so you can run it on a competitor too. The app adds what the outside cannot see: stock units, cost, sales pace, orders and refunds.

Can the app change anything in my store?

No. It asks for four read permissions only: products, inventory, locations and orders. It cannot change a price, a product, a discount or an order. Every fix is something you do yourself.

Does it read my customers’ personal data?

No. The app never reads or stores a customer’s name, email address, postal address or phone number. It does not read who placed an order at all.

What if I have not entered cost per item in Shopify?

The report still runs. Where a cost is missing it assumes a 50% gross margin, marks the figure as estimated and tells you how many variants have no cost, so you know which numbers to firm up.

How far back does it look?

It asks for up to two years of orders. Shopify gives apps the last 60 days of orders unless it approves access to older ones, which we are requesting. Until then the report says how many days it covers, and ages such as days since the last sale are lower bounds.

How often is the report updated?

Changes to products, stock, orders and refunds reach the app within seconds through Shopify webhooks, and every finding is recalculated each night. You can also run the diagnosis again at any time.

Which languages is it in?

Fourteen: English, German, French, Spanish, Italian, Dutch, Portuguese (Brazil), Japanese, Chinese (Simplified), Chinese (Traditional), Korean, Swedish, Danish and Polish. The app follows the language your Shopify admin is set to, and the weekly email comes in the same languages.

Where is my data stored, and what happens when I uninstall?

On Mufatech’s own server with Hetzner in Germany, with daily backups on Cloudflare R2. When you uninstall, Shopify asks for the store’s data to be erased 48 hours later, and everything held about the store is deleted then.

How is this different from Shopify’s own reports?

Shopify’s reports show sell-through, days of inventory, profit and sales by discount code. Store Diagnosis reads the same data, decides which of it is a problem, puts an amount of money on each problem, ranks them, and gives the steps to fix each one.

STORE DIAGNOSIS · SHOPIFY APP STORE

See your own store’s figures.

Store Diagnosis is free on the Shopify App Store. Install it, approve four read permissions, and the first report arrives within a minute or two.

Install from the Shopify App Store Start with the dead stock guide ↗

Read-only and free. Uninstall any time; your store data is erased 48 hours later.

  • Price Free · no billing
  • Access Read-only · 4 scopes
  • Areas Stock · stockouts · margin · profit
  • Languages 14 · app and email
  • Weekly email Mondays · optional