A wide export often carries far more than you need. You want the email column for a mailing list, or just the name and total from a report with twenty fields. Deleting the other columns in a spreadsheet works, but it is fiddly and easy to remove the wrong one. Extracting the columns you want is cleaner.
The short version: paste a CSV or drop a file, tick the columns to keep, arrange them, and download. The extract column tool runs on your device, so nothing is uploaded.
Keeping columns beats deleting them
When you only need a few columns out of many, it is tempting to delete the rest. The problem is that deleting is destructive and error-prone: one stray removal and a column you needed is gone, and you have to start over from the original.
Choosing what to keep flips that around. You start from nothing and add only the columns you want, so the output contains exactly those and nothing else. The source file is never touched, so there is no way to lose data you meant to keep.
Reordering comes free
Extraction is not only about removing columns. Because you build the output column by column, you also decide their order. If a downstream tool expects the ID first and your file has it third, put it first as you pick it. The same step that trims the file also arranges it.
How to extract columns
Step 1: Add the CSV
Paste CSV text into the tool or drop in a .csv file. If the first row holds column names, the columns are listed by name; otherwise they are listed by position.
Step 2: Pick and order the columns
Tick the columns you want. Use the controls to move them up or down into the order you need in the result. The preview updates as you go.
Step 3: Copy or download
Copy the trimmed CSV to paste elsewhere, or download it as a file with only your chosen columns.
Related trimming
If you need fewer rows rather than fewer columns, splitting the CSV breaks it into smaller files, by row count or by a column value. And if the whole table is in the wrong orientation, transposing it swaps rows and columns so the data reads the other way.