Merge CSV Files

Exports rarely come as one file. Banks give one CSV per month, shops one per store, survey tools one per wave, and colleagues send their own copies of the same sheet. Before you can sort, filter or chart the data, it all has to be in one table. This tool stacks any number of CSV and Excel files into a single table in your browser.

Adding the files

Drop all the files at once, or add more later. CSV files with commas, semicolons, tabs or pipes are recognized automatically, and their text encoding is detected, so accents survive. Excel workbooks contribute every sheet, each as its own table. The list shows every file with its row count, and you can remove one that does not belong.

Matching columns by header

“By header name” is the right choice for most exports. Columns are lined up by their names, so it does not matter whether one file lists Date first and another lists it third. With “Ignore case and extra spaces” switched on, “Amount”, “amount” and “Amount ” count as the same column, which helps when files come from different people or program versions.

When files have different columns

Every column that appears in any file is kept, in the order it first appears. Rows from a file that lacks a column simply get an empty cell there. A notice above the result lists which file is missing which columns, so you notice when, say, February’s export dropped the Card column. Nothing is silently discarded.

Matching by position

“By position” puts column 1 under column 1, column 2 under column 2 and so on, using the first file’s header. Use it when files have no header row, or when the headers are in another language but the layout is identical. If the first row of your files holds data rather than names, switch off “Files have a header row”.

Knowing where each row came from

The Source column adds the file name to every row, and for workbooks the sheet name too. That keeps the merged table traceable: you can filter by month, check a suspicious value against its original file, or pivot by source later. Switch it off if the destination system does not expect it.

Your values stay exactly as written

Every cell is copied as text. Customer numbers like 007 keep their zeros, ZIP codes like 02134 stay intact, and 16-digit card or order numbers are not rounded. Only when you save as Excel are plain numbers and ISO dates stored as real values, and codes with leading zeros still stay text.

Saving the result

Download the merged table as CSV, as an Excel workbook, or as TSV. For CSV you can choose the separator and whether to add a byte order mark, which helps Excel display accented characters correctly.

After merging

Merged exports often contain the same record twice, for example when two monthly files overlap. Run the result through Dedupe CSV to remove repeats, or summarize it with the CSV Pivot Table. If you work with workbooks that hold one tab per month, Combine Excel Sheets offers the same matching with sheet selection.

Privacy

The files are read and merged on your device. Bank statements, customer lists and payroll exports are never uploaded.