What a sync audit is, and why copying is not enough
Copying a product into another store takes a second and works on the first day for everyone. The question that matters is the one you ask on day ninety: are the two stores still the same right now? An audit is the machinery that answers it with a list instead of a reassurance.
Why stores drift apart
Nothing dramatic has to happen. A webhook is delivered while the app is restarting and never retried. Someone edits a product in the store that was supposed to only receive them. A supplier feed renames a variant, so the app can no longer tell which variant is which. A second app writes stock for its own reasons. Any of these leaves two stores that were identical yesterday and are not today.
The failure is quiet by nature: the app that copied the product has no reason to look at it again, so nobody notices until a customer orders something you do not have.
What an audit actually compares
A real audit reads both stores and compares values, not its own records of what it once wrote. StoreTwin loads the product from each store and lines up the fields: title, description, status, tags, options, your metafields, and for every variant the SKU, barcode, option values, weight and available stock per location.
Comparing against your own journal instead of the live store is the common shortcut, and it hides exactly the failures worth catching: if the write never landed, the journal still says it did.
How often, and why twice
Every hour StoreTwin re-checks what changed since the previous run. That is cheap and catches the ordinary case quickly. Every night it loads the complete catalogue of both stores and compares them in full, which is the only way to notice a product that changed while nobody was watching, or one that stopped being matched at all.
Both checks write a report. You can also run one yourself from the connection page when you want an answer immediately.
What a useful report says
A green checkmark is not a report. A report names the product, the field, and what each store says: stock of variant "S" is 5 in one store and 3 in the other, this description differs, this product exists only in the receiving store. Anything less leaves you doing the comparison by hand, which is the work you were paying to avoid.
When syncing is on, StoreTwin repairs the difference in the same run and the next check reports that the stores match. When a product is outside what you chose to sync, the difference is still reported and marked as reported only, so you can see it without being told it will be fixed.
The audit as a product of its own
This is why the free plan of StoreTwin audits a catalogue of any size, including one another app is syncing. If you already run a sync app and want to know whether it is telling you the truth, that is a reasonable thing to check without changing anything, and it costs nothing.
How the whole thing works · When stock is out of sync · Pricing