Most failed bulk uploads come from four things: stray whitespace, duplicate SKUs, inconsistent column headers, and numbers stored as text. Fixing them before you import saves hours of fixing listings afterwards.
The four usual culprits
Whitespace. A trailing space in a SKU makes it a different SKU. This is the single most common cause of duplicate products appearing after an import.
Duplicate rows. Usually created by merging exports from two sources, and the platform will happily create both.
Header mismatches. "Price" versus "price" versus "Item Price". Import tools are less forgiving than you expect.
Numbers as text. A price stored as "12.99 " with a space, or with a currency symbol, imports as zero or fails the row entirely.
The CSV Cleaner handles trimming, duplicate removal and header tidying in the browser, so your product data never gets uploaded to a third party.
Before you import
- Import ten rows first as a test. Always. Fixing ten mistakes is a coffee break; fixing eight hundred is a weekend.
- Keep an untouched copy of the original export.
- Check the character encoding if you use accented characters or non-Latin scripts, or they arrive as question marks.
- Confirm your price column is a plain number with no symbol and no thousands separator.
Price the catalogue before you upload it
A bulk import is the cheapest moment to fix pricing across a whole range, because you are touching every row anyway. Work out the price that hits your target margin with the Markup vs Margin Calculator rather than carrying forward numbers you set two years ago.
After the import
Spot-check ten listings at random on the live site, not in the dashboard. Look at price, images, variants and stock. Errors that survive an import are usually invisible in the admin and obvious to a buyer.