Find Duplicate Rows in Google Sheets

There are many ways to find Duplicate Records in Google Sheets. You can do it manually using various spreadsheet formulas or you can use Google Apps Script.

This script, uploaded by Carl Kranich to the Google Drive Template Directory, finds duplicate rows in the active sheet and colors them red but unlike other methods, here you have the option to find duplicates based on data of specific columns.

For instance, if the first column is name and the second is age, you can set the value of CHECK_COLUMNS array as 1,2 and the script will only use these 2 columns to catch the duplicate entries. The columns may be contiguous or noncontiguous.