Merge CSV files
Combine several CSV files into one. Columns are matched by their heading, so files with columns in a different order or a missing column still line up.
Columns are matched by their heading, so files with columns in a different order still line up.
Your files are merged on this device. Nothing is uploaded.
Merging by heading, not position
The simple way to merge CSVs is to paste one below the other and it works until two files disagree about their columns. Exports from the same system change over time: a field is added, another is renamed, the order is shuffled by an update. Pasting by position then puts phone numbers under the email heading with nothing to warn you.
This tool reads each file's headings and places every value under the matching column. The merged file has every column that appears in any file, in the order they first appear.
Duplicates
Overlapping exports, such as two date ranges that share a day, produce duplicate rows. Tick Remove duplicate rows to keep only the first copy of each exact match. Rows that differ in any column, even by a space, are kept, so tidy the files with theCSV cleaner first if that matters.
Order
Rows are kept in file order, then in their original order within each file. Use the arrows to change which file comes first. The output is a standard comma separated file whatever the inputs used, ready to convert to Excel if needed.
Common questions
What if the files have columns in a different order?
They’re lined up by heading, not position. A file with email before name merges correctly with one that has name before email. Headings are matched ignoring capitals and surrounding spaces, so Email and email count as the same column.
What if one file has a column the others don’t?
The merged file includes it and rows from files without it get an empty cell in that column. The file list shows which files add or lack columns, so a renamed column is easy to spot before you rely on the result.
Can I tell which file each row came from?
Tick Add a column with the source file name and every row carries its file name in a final column. It is invaluable when monthly exports are merged and one month turns out to be wrong.
Does it merge side by side, joining on a key?
No. This stacks files on top of each other, which is what merging exports usually means. Joining two tables on a shared ID column is a lookup, which a spreadsheet or database does better.
Are my files uploaded?
No. They’re read and combined in your browser. Customer lists and sales exports never leave your device.
Guides
The other tools
All of them work the same way: the file is read in your browser and never uploaded.