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SheetTidy

Remove duplicates from Excel and CSV files

Find repeated rows by whole row or by the columns you choose, preview them, then download a clean copy.

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Drop your Excel or CSV file here

XLSX, XLSM, XLS, ODS, CSV, TSV or JSON

Your file never leaves your device

How to use this tool

  1. Step 1: Open your file

    Drop an .xlsx, .xls or .csv file onto the tool, or choose it from your computer. If the workbook has several sheets, pick the one to clean.

  2. Step 2: Decide what counts as a duplicate

    Keep the default to remove rows where every column matches, or choose specific columns such as Email or Customer ID.

  3. Step 3: Check the preview

    Duplicate rows are marked in the Before view, and the summary tells you how many will go and how many rows remain.

  4. Step 4: Download the clean file

    Save the result as Excel or CSV. If you want a record of what was removed, download the removed rows as a separate file.

How to remove duplicates manually in Excel

Excel has several built-in ways to deal with repeated rows. Each works, but each has a catch worth knowing about before you rely on it.

The Remove Duplicates command

  1. Click any cell inside your data.
  2. On the Data tab, in the Data Tools group, click Remove Duplicates.
  3. Leave My data has headers ticked if the first row holds column names.
  4. Tick the columns that must match for two rows to count as duplicates. Leaving every column ticked removes only exact copies.
  5. Click OK. Excel reports how many duplicate values it removed and how many unique values remain.

Excel keeps the first occurrence and deletes the rest in place. It ignores capital letters, so “ACME Ltd” and “acme ltd” match, but it does not ignore spaces: “Priya Shah” and “Priya Shah “ (with a trailing space) are treated as two different people. That trailing space is invisible in the cell, which is why duplicates often survive this command. Run a trim first, or use a tool that ignores spacing while it compares.

Highlight duplicates before deleting

If you would rather look before you delete, select a column and choose Home › Conditional Formatting › Highlight Cells Rules › Duplicate Values. This colours repeated values in that column. It works cell by cell, not row by row, so to highlight whole duplicate rows you need a helper column that joins the key fields, for example =A2&"|"&C2, and then a COUNTIF on that helper column.

The UNIQUE function

In Excel for Microsoft 365 and Excel 2021, =UNIQUE(A2:D500) returns the distinct rows of a range into a new area of the sheet, leaving the original untouched. Like Remove Duplicates, it ignores case but not extra spaces, and the result is a formula, so you need to copy it and use Paste Special › Values before you can edit or sort it freely.

Advanced Filter and Power Query

Older versions can use Data › Advanced with Copy to another location and Unique records only ticked. Power Query offers Home › Remove Rows › Remove Duplicates, but note that Power Query compares text case-sensitively, so it treats “Rahul Mehta” and “RAHUL MEHTA” as different, which is the opposite of the Excel command.

When this tool helps

Merged contact lists. You export customers from a CRM and leads from a web form, paste them into one sheet and need a single list. The same person often appears in both, sometimes in capitals in one system and with a stray space in the other. Comparing on the Email column alone, with case and spaces ignored, catches these.

Overlapping bank or sales exports. Downloading transactions for 1–15 March and then 10–31 March gives you six days twice. Comparing whole rows removes the overlap without touching genuine repeat purchases that differ in amount or time.

Survey and form responses. People press Submit twice. Keeping the last copy keeps the most recent answer if they corrected something on the second attempt.

Product and stock lists. A supplier sends a price list where the same SKU appears on two pages. Comparing on the SKU column with the default settings leaves one line per product.

What the tool does differently

  • It ignores case and extra spaces by default. Most “missed” duplicates in Excel are caused by a capital letter or an invisible space. Both settings can be turned off under More options.
  • It never treats empty rows as duplicates. Two rows with no email address are not the same customer. If you compare on Email, rows with a blank email are always kept.
  • It shows you before it deletes. The Before view marks every row that will be removed, and the summary states the exact count. Nothing changes until you download.
  • It can mark instead of delete. The flag option adds a column such as “Duplicate of row 4”, so you can review and decide in Excel.
  • It keeps what it removed. After running, you can download the removed rows as their own file, which is a simple audit trail when you clean shared data.
  • It preserves your values. Customer codes like 000123 keep their leading zeros, dates stay dates and text in any language comes through unchanged.

Choosing the right columns

Think about what identifies one record in your data. For people, an email address or customer ID is usually best; names alone are risky because two different people can share one. For transactions, whole-row comparison is safest, because two genuine payments can share a date and an amount but differ in reference number. When in doubt, use the flag option first, check the marked rows in the preview, then run the tool again in remove mode.

Once duplicates are gone, the file check on this page may suggest a next step, such as trimming spaces from names or making capitalisation consistent, so the list is fully tidy before you import it anywhere else.

Frequently asked questions

Which copy of a duplicate row is kept?

The first one, nearest the top of the sheet, just like Excel's own Remove Duplicates command. Under More options you can keep the last copy instead, which is useful when newer records are added at the bottom.

Is the comparison case-sensitive?

Not by default. "RAHUL MEHTA" and "Rahul Mehta" are treated as the same person, and extra spaces are ignored too. You can switch either setting off if capitals or spacing matter in your data.

Can I find duplicates based on one column, such as email address?

Yes. Choose "Rows that match in the columns I choose" and tick the Email column. Rows that share an email address are treated as duplicates even if their other columns differ.

Can I see the duplicates without deleting them?

Yes. Under More options, choose to keep every row and mark duplicates. A new Duplicate column is added that says which row each copy repeats, so you can review them in Excel.

What happens to blank rows?

Rows whose compared cells are all empty are never treated as duplicates of each other, because missing data is not the same record. Use the Remove blank rows tool to delete them.

Will leading zeros and special characters survive?

Yes. Codes such as 000123 stay as text, and names in any language, including Hindi and Gujarati, are kept exactly as they were.

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