You can remove leading, trailing, and extra spaces between characters and numbers in Excel using TRIM(), SUBSTITUTE() or Find and Replace.

Removing these leading spaces – or trailing spaces that fall at the end of a cell's contents – requires an Excel function.

To clear formatting from the selected cells in your workbook in Microsoft Excel, you can use Clear Formats, Keyboard shortcuts, Format Painter tool, etc.

Look for extra spaces in your values' cells. If your duplicate values have extra spaces in their cells, those spaces will also cause the Remove Duplicates tool to consider them to be unique values.