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How we handle your data

Local CSV utility

Compare Two CSV Files

Match rows of two CSV files by a unique key and list added, removed and changed rows with old and new values.

CSV files stay in your browser.

Old CSV file
New CSV file

Up to 10 MB and 100,000 rows per file, 500 columns. Files are read in your browser and are not uploaded.

Try an example

“Try a sample” loads these files:

Old CSV file

id,value
A,10
B,20

New CSV file

id,value
B,25
C,30

Expected result: Key id: 1 added (C), 1 removed (A), 1 changed (B: value 20 → 25), 0 unchanged.

Other CSV tasks

Remove Duplicate Rows from CSVRemove rows that repeat the same values in the columns you choose. Keep the first or last copy and download the removed rows too.Validate CSV FieldsCheck required values, whole numbers, numbers, ranges and allowed values column by column. Every problem is listed with its row and column; the file is not changed.Merge CSV FilesAppend the rows of two CSV files into one file. Columns are matched by name, not position; files with different columns need your explicit choice.Split CSV FileSplit a large CSV file into smaller files with a set number of rows. Every file keeps the header row; cells with line breaks stay whole.CSV structure checkerCount rows, columns, empty cells and inconsistent rows.