About Remove Duplicates
Clean up mailing lists, CRM exports and transaction logs. Decide which columns define a duplicate, ignore case and extra spaces, and keep the first or last occurrence.
How to use Remove Duplicates
- Drop your spreadsheet.
- Select the columns that define a duplicate and set the matching options.
- Click “Remove duplicates” and download the cleaned file (and optionally the removed rows).
Limitations
- Everything runs in your browser’s memory, so the practical file size depends on your device. As a rough guide: up to ~50 MB or ~500,000 rows works well on a modern laptop; phones and tablets handle much less.
- Very large files can make the tab slow or crash. If that happens, split the file first or use a desktop computer.
- Outputs keep values and formulas’ results but not formatting, charts, images, pivot tables or macros.
Frequently asked questions
Can I dedupe by email only?
Yes — select just the email column.
Is “John ” the same as “john”?
With “Ignore case” and “Ignore extra spaces” on, yes.
Can I see what was removed?
Yes, download the removed duplicates as a separate file.
Disclaimer: Excel Tools by gumber.ai is a hobby project and is completely free to use. It is provided “as is”, without warranty of any kind. Always double-check results before relying on them, and keep a copy of your original files.
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