I needed to de-dupe a spreadsheet the other day and found a great how-to from google. Thought I’d post it here for my own future purposes:
There is no automatic function to remove duplicate rows. Follow these steps to delete all rows that have duplicate values in column A:
- Select all cells of the current data range.
On most systems, you can click any cell inside the data range, then press Ctrl+Multiplication key on the numeric keypad. - Sort the data range by column A.
Choose Data – Sort. - Click an empty cell in the first row. Let’s assume it is cell C1. Enter the formula:
=IF(A1=A2;1;0)
This will display 1 if the current row has the same value in column A as the next row. It will display 0 if the values are different.
- Copy the formula down for all rows of the data range.
Drag the lower right edge of the cell C1 down to the last row. - Now the formulas must be replaced by their values to freeze the contents.
While the column C is still highlighted, press Ctrl+C to copy all selected cells to the clipboard. - Press Shift+Ctrl+V to open the Paste Special dialog box.
In the Selection area, enable only the Numbers command; disable the other Selection commands. Click OK. - Select the whole data range including the new column C and sort the range by column C.
Choose Data – Sort. - Select all rows which have a value 1 in column C, then press Del key.
- Optional steps: Delete column C. Select the remaining rows and sort them again by column A.

