How to highlight cell if value duplicate in same column for google spreadsheet?

Question

I am looking for formula for google spreadsheet highlight cell if value duplicate in same column

can anyone please assist me for this query?

Answer 1

I tried all the options and none worked.

Only google app scripts helped me.

source : https://ctrlq.org/code/19649-find-duplicate-rows-in-google-sheets

At the top of your document

1.- go to tools > script editor

2.- set the name of your script

3.- paste this code :

function findDuplicates() {
  // List the columns you want to check by number (A = 1)
  var CHECK_COLUMNS = [1];

  // Get the active sheet and info about it
  var sourceSheet = SpreadsheetApp.getActiveSheet();
  var numRows = sourceSheet.getLastRow();
  var numCols = sourceSheet.getLastColumn();

  // Create the temporary working sheet
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var newSheet = ss.insertSheet("FindDupes");

  // Copy the desired rows to the FindDupes sheet
  for (var i = 0; i < CHECK_COLUMNS.length; i++) {
    var sourceRange = sourceSheet.getRange(1,CHECK_COLUMNS[i],numRows);
    var nextCol = newSheet.getLastColumn() + 1;
    sourceRange.copyTo(newSheet.getRange(1,nextCol,numRows));
  }

  // Find duplicates in the FindDupes sheet and color them in the main sheet
  var dupes = false;
  var data = newSheet.getDataRange().getValues();
  for (i = 1; i < data.length - 1; i++) {
    for (j = i+1; j < data.length; j++) {
      if  (data[i].join() == data[j].join()) {
        dupes = true;
        sourceSheet.getRange(i+1,1,1,numCols).setBackground("red");
        sourceSheet.getRange(j+1,1,1,numCols).setBackground("red");
      }
    }
  }

  // Remove the FindDupes temporary sheet
  ss.deleteSheet(newSheet);

  // Alert the user with the results
  if (dupes) {
    Browser.msgBox("Possible duplicate(s) found and colored red.");
  } else {
    Browser.msgBox("No duplicates found.");
  }
};

4.- save and run

In less than 3 seconds, my duplicate row was colored. Just copy-past the script.

If you don't know about google apps scripts , this links could be help you:

https://zapier.com/learn/google-sheets/google-apps-script-tutorial/

https://developers.google.com/apps-script/overview

I hope this helps.