Shopify set all my stock to zero after I uploaded my spreadsheet
Your upload finished without errors. Shopify told you it succeeded. Then you looked at your products and every single quantity read 0. No alert. No explanation. Here is exactly what happened and how to make sure it never happens again.
What to do right now
Do not upload anything again until you have verified the file. Stock isn't lost — it was overwritten with zero, and you fix it by uploading a corrected file with the right numbers (that is a second upload, not an undo). If you still have the original quantities somewhere — in a backup export you ran before, in a warehouse system, in a spreadsheet you maintain manually — you can restore them.
To check your corrected file before uploading, use the free tool below. Upload your spreadsheet and it will show you every row where the tracker is set but the quantity is blank or zero, alongside a plain-English summary of what the import would write to your store. Nothing reaches Shopify until you choose to download the fixed file and upload it yourself.
How to tell this happened to you
Open any product in your Shopify admin and look at the Inventory section.
If quantities you know should be non-zero are all showing 0 — and your
import email said "Completed successfully" — you've hit this exact problem.
It is not a partial failure. The import ran correctly; it just wrote the wrong number.
The root cause (plain language)
Shopify's inventory CSV has two key columns that work together. The first,
Variant Inventory Tracker, controls whether Shopify tracks stock for a
variant at all. When it contains shopify, Shopify watches that variant's
quantity and stops sales when stock hits zero.
The second column — which goes by different names depending on how you got the file —
holds the actual quantity number. In Shopify's native inventory export
it's labeled On hand (new). In older exports and third-party templates it's
often called Variant Inventory Qty.
Here is the trap: if Tracker is set to shopify but the quantity
cell is blank, Shopify reads that blank as the number zero and writes it.
Every row where this combination exists gets zeroed out during the import — silently,
with no row-level warning in the import email.
Three ways this ends up in your file
- You exported from Shopify and then sorted or filtered in Excel. Sorting can move rows so the quantity column no longer lines up with the right tracker row. The tracker says "shopify"; the quantity that landed next to it belongs to a different product and is blank.
- You built the file from scratch and forgot to fill in quantities. It's easy to add every SKU with proper tracker values and then realize you haven't filled the numbers column yet — but upload it anyway by mistake.
- You copied the file into Excel and it dropped leading zeros or converted numbers to scientific notation in the SKU column. Now no rows match existing products by SKU. Shopify creates new tracked variants at zero rather than updating existing ones.