Excel Toolbox
Data Tools

Excel Deduplication

Remove duplicate records from your Excel files based on one or more columns, keeping everything else in the row. Your data is processed entirely in your browser and is never uploaded to any server.

  • Nothing uploaded
  • No size limit
  • No account

Drag and drop an Excel file here, or click to select

What the Excel Deduplication tool does

Duplicate rows creep into a spreadsheet whenever data is exported twice, combined from several sources, or pasted in by hand. This tool removes duplicate rows from an Excel file based on the columns you choose, so a repeated customer, order or email address is reduced to a single row. You decide which columns identify a duplicate — everything else in the row comes along for the ride.

How to remove duplicate rows in Excel

  1. Add your workbook

    Drag an .xlsx or .xls file onto the drop area, or click it to browse. The first few rows appear straight away so you can check you picked the right file.

  2. Choose the columns that identify a duplicate

    Tick one column to catch repeats of a single value, such as an email address, or tick several to treat rows as duplicates only when every one of those columns matches.

  3. Decide how values are compared

    Keep the first or the last copy of each duplicate group, and choose whether capitalization and stray spaces should count as a difference.

  4. Remove the duplicates

    You get a summary of how many rows went in, how many duplicates were removed and how many remain, and the cleaned workbook downloads automatically.

Options explained

Keep first occurrence
On by default: the earliest row in a duplicate group survives. Turn it off to keep the last one instead, which is what you usually want when later rows hold the more recent data.
Case-sensitive comparison
On by default, so "ACME" and "Acme" are treated as different values. Turn it off to fold them together — useful for names and email addresses.
Trim leading and trailing spaces
On by default, so "Acme " matches "Acme". Spaces inside a value are always kept as they are.

What stays on your device

Your workbook is never uploaded. The Excel Deduplication tool reads the file straight from your disk and does all of its work inside this browser tab, using the open-source ExcelJS and SheetJS libraries. There is no account, no upload limit and no copy of your data on any server — once this page has loaded, the tool keeps working even if you disconnect from the internet.

Limitations to know about

  • Only the first worksheet in the workbook is processed.
  • The result is a fresh workbook containing your headers and data. Cell formatting, formulas and charts from the original are not carried across — keep your original file if you need them.
  • Numbers and text that look alike are treated as different, so the number 1 does not match the text "1". This matches how Excel's own Remove Duplicates behaves.
  • A legacy .xls file is converted to .xlsx before processing, which preserves the data but not the original formatting.

Frequently asked questions

How do I remove duplicates in Excel without losing the rest of my data?

Pick only the columns that define a duplicate — an email address or an order number, say — rather than every column. Rows are compared on just those columns, and the surviving row keeps all of its other values. Nothing outside the duplicate rows is touched.

Does it compare the whole row or only some columns?

Only the columns you tick. If you tick several, a row counts as a duplicate only when all of those columns match. To remove rows that are identical from end to end, tick every column.

Should I keep the first or the last occurrence?

Keep the first when your file is in the order the records were created and the earliest entry is the authoritative one. Keep the last when rows were appended over time and later rows hold updated values.

Why does it say no duplicates were found?

No two rows matched on every column you ticked. Try ticking fewer columns, or turn off case-sensitive comparison — values such as "acme" and "Acme" count as different while that option is on.

Are my files uploaded to a server?

No. Every tool on Excel Toolbox runs in your browser using the open-source ExcelJS and SheetJS libraries. Your workbook is read from your own disk, processed in your browser tab, and written back out as a download. It is never sent to us or to anyone else, which is why the tools keep working if you go offline after the page has loaded.

How large a file can I process?

There is no upload limit, because nothing is uploaded — the ceiling is your device's memory. Files up to about 25 MB are comfortable on a typical laptop. Much larger workbooks will still work but take longer, and processing runs in the page, so leave the tab open until your download starts.

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