Online tools
Remove duplicate rows from Excel or CSV online
A free Duaer tool: open an Excel or CSV file, pick the columns that define a duplicate, keep the first row, optionally ignore case and spaces, and see how many rows were removed. No upload.
How to use it
- Drop an Excel or CSV file into the box above, or paste CSV and click "Convert".
- Tick the columns that define a duplicate, such as only "Phone"; tick none to compare whole rows.
- Check how many rows were removed, then click "Download .xlsx" or "Download .csv".
Rules
- Rows are read top to bottom; the first row for each key stays and later ones are removed. To keep the newest, sort by date descending in Excel first.
- Cells are compared by displayed text. With "Ignore case and surrounding spaces", `A@x.com ` and `a@x.com` count as duplicates.
- For Excel files, the first sheet is read.
Automate it in Duaer
In Duaer, use the Remove Duplicates node with Remove Items Repeated Within Current Input and the fields to compare. To skip items seen in earlier runs, use Remove Items Processed in Previous Executions. See Remove duplicates.
Questions
How do I keep the last occurrence instead?
The Duaer tool keeps the first occurrence. Sort the table newest first in Excel, then deduplicate with Duaer to keep the latest row.
Can I see which rows were removed?
The Duaer tool reports only the count. To review rows one by one, highlight duplicates with conditional formatting in Excel first.
In this section
Free file converters from Duaer
Free Duaer tools for spreadsheets and data files: convert formats, merge, split, remove duplicates, fix encodings, and format JSON. Everything runs in your browser and no file is uploaded.
File conversionMerge Excel and CSV files online (columns matched by header)
A free Duaer tool: pick several Excel or CSV files, match columns by header name, and get one table with an optional source-file column. No upload.
File conversionSplit an Excel table by column online (one sheet per value)
A free Duaer tool: pick a column such as department, region, or store, and get one sheet per value, or download any group as CSV. No upload.
SnippetsRemove duplicates in Duaer, within a run and across runs
Remove Duplicates in Duaer drops repeats within one batch, and can remember what earlier runs handled so a schedule processes only new items.