How to Remove Duplicate Lines From a Spreadsheet Column

Spreadsheet columns are easy to copy, but they often include hidden problems: blank cells, leading spaces, trailing spaces, repeated values, and inconsistent capitalization. If you only use a spreadsheet's built-in duplicate removal, you may miss entries that look the same to a person but not to the software.

Example input copied from a column

Blue Widget
 blue widget

Red Widget
Red Widget 
Green Widget
GREEN WIDGET

Recommended workflow

1. Paste the copied column into CleanTextTool.
2. Click Trim Whitespace to remove spaces at the start and end of each line.
3. Click Use to continue from the cleaned output.
4. If capitalization does not matter, click lowercase.
5. Click Use, then click Remove Empty Lines.
6. Click Use, then click Remove Duplicates.
7. Optional: click Sort A to Z for easier review.

Clean output

blue widget
green widget
red widget

When not to lowercase

Do not lowercase everything if capitalization carries meaning. Product codes, acronyms, names, and case-sensitive IDs may need to keep their original form. In that case, trim whitespace and remove empty lines first, then review duplicates manually.

Quality check before pasting back

Use the line counter under the output box. If you expected 200 rows and the output has 80, that may be correct after deduplication, but it is worth checking before replacing your spreadsheet data.