Keep one row per email address in a mailing list, ignoring case and stray spaces
Processed in your browser. Nothing is uploaded. Checked against sources on 17 Oct 2026.A mailing list exported from two tools usually holds the same person twice: [email protected] in one, [email protected] with a trailing space in the other. Drop the CSV or Excel list here, tap the Email column, and every repeat is found with case and spaces ignored, so one row per address remains. The first copy is kept with its name and other columns; the removed rows can be downloaded to review.
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Adjust the options and check the preview.
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Duplicate rows creep in whenever two exports are combined, a form is submitted twice or a list is copied from several places. Finding them by eye stops working after a few hundred rows.
| Option | What it does |
|---|---|
| Whole row | Two rows match only when every column matches |
| Chosen columns | Rows match when those columns match, such as Email or Order number |
| Ignore upper and lower case | [email protected] and [email protected] are the same |
| Ignore extra spaces | Spaces at the ends of a cell, and doubled spaces inside, do not count |
| Keep the last copy | The newest row of each group survives instead of the first |
| Remove empty rows | Rows with nothing in them go as well |
The header row is never compared, and the rows that stay keep their original order, so nothing is resorted.
The rest of the article, and all 6 questions about Remove Duplicate Rows (CSV and Excel), are on the Remove Duplicate Rows (CSV and Excel) page.
Drop the CSV on Remove Duplicate Rows. Duplicates are counted at once, comparing whole rows, and the first rows that would be removed are listed. Tap a column such as Email to compare only that column, then press Download to save the cleaned CSV with its header and delimiter unchanged.
Drop the .xlsx here and tap the column that identifies a row, for example Customer ID. Rows with a value already seen in that column are removed and the first one stays. The download is a new .xlsx with the kept rows, their numbers, dates and formats unchanged.
The first copy of each repeated value is kept by default, and the kept rows stay in their original order. Tick Keep the last copy when the newest row should win, such as the latest address of a customer who signed up twice.
Values that look the same may differ in case or spacing, such as [email protected] and [email protected] with a trailing space. Tick Ignore upper and lower case and leave Ignore extra spaces on. Numbers stored as 42 and 42.0 count as different text.
Rates and rules change; check the source before you rely on a figure.
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