Prevent duplicates before they happen by combining a simple function with data validation. Excel has built-in tools to expose and even delete duplicates, but they work on existing data after the fact.

Learn how the new Excel Copilot function simplifies data cleanup, automates tasks, and boosts productivity for analysts and beginners alike.

Duplicates in the same column are easy to find by sorting, filtering, and using conditional formatting. When none of those are an option, try this simple formula solution.