Find Duplicate Values Online

Paste a list to see which values repeat and how many times — nothing is deleted.

100% private. Everything runs in your browser. Your data never leaves your device.

Find Duplicates

What does this tool do?

This tool finds duplicate values in a list and shows you exactly which values repeat and how many times, without deleting anything. Paste a column or upload data, and it groups the repeats for you. Everything runs in your browser.

How to use Find Duplicates - Free Online Tool

  1. Paste your values (one per line) or click "Try with sample data".
  2. Choose whether to ignore letter case and extra spaces.
  3. Click Find Duplicates.
  4. Review the duplicated values and their counts, and copy or export the list.

Example

Finding repeated order IDs:

Before

Order
A1
A2
A1
A3
A2
A1

After

Value Count
A1 3
A2 2

A1 appears 3 times and A2 twice; A3 is unique.

Excel formula alternative

Prefer a formula? You can achieve a similar result with COUNTIF:

=COUNTIF(A:A, A2) > 1

Excel's COUNTIF flags values that appear more than once. This tool lists every duplicate with its count in one click.

When should I use this tool?

Spotting repeated IDs or order numbers
Auditing a list before removing duplicates
Finding double-entered records
Checking survey responses for repeats
Counting how often each value occurs
Data quality checks before analysis

Frequently Asked Questions

No. This tool only finds and counts duplicates so you can review them. Use the Remove Duplicates tool if you want to delete them.

No. Everything runs in your browser and your data never leaves your device.

Yes. Both options are available so "Apple", "apple" and " apple " can be treated as the same value.

Tens of thousands comfortably, limited only by your device memory.

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