Filter For Unique Values Or Remove Duplicate Values - Microsoft Support

Remove duplicate values

When you remove duplicate values, the only effect is on the values in the range of cells or table. Other values outside the range of cells or table will not change or move. When duplicates are removed, the first occurrence of the value in the list is kept, but other identical values are deleted.

Important: You can always select Undo to get back your data after you have removed the duplicates. That being said, it's a good idea to copy the original range of cells or table to another worksheet or workbook before removing duplicate values.

Follow these steps:

1. Select the range of cells or ensure that the active cell is in a table.

2. On the Data tab, select Remove Duplicates.

3. In the Remove Duplicates dialog box, unselect any columns where you don't want to remove duplicate values.

   Note: Data will be removed from all columns, even if you don't select all the columns at this step. For example, if you select Column1 and Column2, but not Column3, then the “key” used to find duplicates is the value of BOTH Column1 & Column2.  If a duplicate is found in Column1 and Column2, then the entire row will be removed, including data from Column3.

4. Select OK, and a message will appear to indicate how many duplicate values were removed. Select OK to dismiss this message.

Note: If you want to get back your data, simply select Undo (or press Ctrl+Z on the keyboard).