I know there is app on Monday.com but its a paid app for a basic function for checking duplicates. Can this be a feature can add as a feature?
Hello @Arjun21 , you can manually check for duplicates based on a column after you’ve added an item… But if you want the duplicates to be checked as you are adding, I think your assumptions are correct.
Hi @Arjun21 , I have found a solution which does not require any paid apps! It only requires some creativity with the automations.
Identifying the new item as a duplicate
This can be achieved using one of the “Connected & mirror columns” automation templates:
”When an item is created in this board, connect the item where this column matches this column in another board by this logic.”
Here’s the trick - even though the prompt says “another board”, you can actually connect it to the same board!
You will need to add a new “connect boards” column to your board. This can be done beforehand or while setting up the automation. You could name it “Duplicate Check”. Then, if the selected columns are a match, a newly created item will automatically display the pre-existing item in the “Duplicate Check” column. The column will be empty for non-duplicate items.
Managing new duplicates
If you want duplicate items to be deleted, you could add a second automation to achieve this:
”When an item is created
and if Duplicate Check is not empty
↓
Then delete item”
Alternatively, if you don’t want duplicates to be deleted, you could program the automation to, “move item to group”, “notify” or “change status”.
Limitations and alternative solutions
This solution won’t work if you create items manually and you want to check for duplicates in fields other than the item “name”. This is because the other data fields will be empty when the automation is triggered. Conveniently, there are “Connected & mirror columns” automation options which use different triggers (status change, column change).
The solutions are quite open ended as long as you remember the trick - you can connect to the same board… even though the automation prompt says “another board”.
I am very pleased to have stumbled upon this unconventional solution! I hope it will also work for you 
If you have Workflows feature, you can do this with the Find Matching Item block. Match it with whatever column you want. Then, if it is found, notify you, or delete the newly created item, or whatever else you’d like to do. What’s great is that you can also exclude the currently created item from your search.
You can have the trigger be when item is created, or get more creative by stating when status changes to “Check for duplicates,” or something similar.
In case anyone is interested in an app that does this, the Duplicates and Uniques app does this. Here is a demo of how