Combine CSV Files

About this tool

Add two or more CSV files and get one combined CSV. Columns are matched by their headings, so files with the same columns in a different order still line up.

The files are read and joined in your browser, so your data never leaves your device.

How to use it

1. Drop your CSV files onto the box, or click it to choose them (two or more).
2. Put them in the order you want. Rows appear in that order in the result.
3. Check the note: it tells you if any columns are missing from some files.
4. Tick whether to add a “Source file” column, name the file and press Combine files.

How the columns are matched

The files are stacked on top of each other, and each column is matched to the others by its exact heading. If one file lists Name, Email and Phone and another lists Email, Name and City, the combined file has Name, Email, Phone and City, with blanks where a file has no such column. “Name” and “name” count as different headings, so fix those first if they differ only by capitals.

Keeping track of where rows came from

Tick “Add a column showing which file each row came from” to add a Source file column holding each row's original file name. It's useful when you combine monthly exports and want to filter or pivot by month afterwards.

Leading zeros, quotes and accents

Every value is kept exactly as text, so codes such as 01234 keep their zero. Commas, quotes and line breaks inside cells are handled correctly. The result is saved with a marker (a UTF-8 BOM) so Excel shows accented characters correctly; untick it if another program complains.

Limits

This free tool combines up to 20 files, with 25 MB in total. Excel workbooks (.xlsx) aren't read directly: in Excel choose File → Save As → CSV for each sheet first.

Frequently asked questions