CSV opens in a single column: check the separator

You open your product file and every row sits in one cell in column A. The header, the SKU, the name and the rest are all joined in one long line of text.

How to tell. Your spreadsheet program splits each line at one character, and the one between your values is not the one it expects. Open the file in a plain text editor and look at the first line (a tab shows as a wide gap). In the synthetic example below, the values are divided by semicolons. A program that expects commas finds none and keeps each line whole. Other files use tabs or a pipe character instead.

Fix steps. 1. Note which character separates the values in the first line: semicolon, tab, pipe or comma. 2. Work on a copy and keep the original untouched. Import the copy instead of double-clicking it, and choose that character when the program asks how to split the text. 3. If the program offers no choice, get the file exported again with the separator your program expects. "Decimal comma or column separator in CSV prices?" explains why a re-export is safer than swapping characters by hand, and how a decimal comma in a price can split a row once commas separate the columns. After a switch to commas, a cell that contains a comma must sit inside double quotes; see "Quotes and commas inside CSV cells: find and fix".

Recheck. Open the new file. Each value should sit in its own cell, with the header names across the top row. Look at the last row to confirm nothing was cut off, and count each row's fields against the header as in the recheck step of "Decimal comma or column separator in CSV prices?". If the whole row is still in one cell, repeat from step 1; the separator you noted may have been the wrong one.

The free CSV check on this site will not catch this problem. It picks the separator from the header row by itself (comma, semicolon or tab), so a semicolon or tab file that opens in one column can pass with no problems. With a pipe or another separator, it usually reports the SKU, title and price columns as missing, even if your file has them.