It’s not unusual to have duplicate occurrences of data in a spreadsheet, and there are numerous reasons why they might need to be removed. More importantly, you want them removed quickly so you can start analyzing the data. Luckily, there are various methods of locating and removing duplicate data in Microsoft Excel.

Note: Because you are permanently deleting data, it’s a good idea to copy the original range of cells or table to another worksheet or workbook before removing duplicate values.

Select the range of cells, or make sure that the active cell is in a table.
On the Data tab, in the Data Tools group, click Remove Duplicates
Under Columns, select one or more columns that contain possible duplicate data. To quickly select all columns, click Select All. To quickly clear all columns, click Unselect All.
Click OK.
Excel displays a message indicating how many duplicate values were removed and how many unique values remain, or if no duplicate values were removed.
Click OK.