Remove Duplicates

This add-on comes with two useful wizards. One will help you compare two different tables or columns and remove duplicates; the other will search for unique and duplicate rows within one sheet. 

Use the "Compare columns or sheets" tool to quickly scan any columns in your tables for the same values. It will take you five simple steps to mark duplicates with colour or status, copy or move them to another sheet, clear repeating cells, or delete entire rows that contain dupes from your main table. 

"Find duplicates or uniques" tool will let you check any combination of columns to look for uniques, dupes, and include their first occurrences in the results. Besides applying the selected action, the add-on will display a summary with the number of found entries.

Remove Duplicates add-on also offers case-sensitive search and additional options for handling empty cells and headers. You can use this tool to make your tables duplicate-free in a flash.

Version 1.2: Take advantage of all Pro features for free: mark duplicates in a separate column, copy or move the found rows to another sheet.

Version 1.5: We fixed the issues you reported and made the add-on much faster!

Feel free to try it out on this test spreadsheet:
http://goo.gl/wHBySu

If you have any questions about the add-on, please post them in our community: http://goo.gl/5aqwsD