How to Find Case-Sensitive Duplicates in Excel

When Case Matters

Case sensitivity matters when abc123 and ABC123 represent different values. This can happen in software exports, API keys, product codes, user handles, inventory labels, and database IDs.

Formula Method

Use EXACT when case matters:

=SUMPRODUCT(--EXACT(A2,$A$2:$A$100))>1

This returns TRUE when the exact same text, including capitalization, appears more than once.

Case-Insensitive Cleanup

If case should not matter, normalize values first with LOWER(TRIM(A2)). This makes North, NORTH, and north comparable.

Use a Duplicate Finder

The Duplicate Row Finder includes matching options for duplicate detection. Use it when duplicates are based on one or more columns, not just a single list.

Before Removing Duplicates

Decide whether you want exact duplicates, case-insensitive duplicates, or duplicate business records. These are different problems and should not be cleaned with the same rule.