Combine several CSV files into one, matching columns by header name, in your browser
Processed in your browser. Nothing is uploaded. Checked against sources on 16 Oct 2026.Merge CSV Files combines up to 200 CSV files into one CSV in your browser, matching columns by header name so files with extra or reordered columns still line up. Each file's delimiter and encoding are detected on their own, nothing is uploaded, and the result opens cleanly in Excel.
Press Select CSV files, or drop several CSV files on the page; each is read on your device.
Check the plan: the columns of the merged file and how many rows each file adds.
Leave Match columns on By header name, or choose By position for files with the same layout and no matching names.
Press Merge, and the combined CSV downloads.
Exports rarely come as one file: a shop gives one CSV per month, a bank one per account, a survey one per region. Copying them together by hand drops header rows in the middle, misaligns columns and breaks quoted fields. This page does the join properly.
Two ways to match columns.
| Match columns | Use it when |
|---|---|
| By header name | files come from the same system but columns were added, removed or reordered |
| By position | the files share one layout but their header names differ, or there are no headers |
By name, a column is the same when its header matches ignoring capital letters and spaces around it, so "Email" and " email" are one column. Columns appear in the order they are first seen, and a row from a file without a column gets an empty cell there. The plan lists which columns each file is missing before anything is merged.
Each file read on its own. The delimiter is detected per file from comma, semicolon, tab and pipe, and the encoding is UTF-8 or, for older Excel exports, Windows-1252. A file with a broken quote is named and left out, and the others still merge.
Options. Add a Source file column puts the original file name on every row. Remove duplicate rows keeps only the first copy of rows that are identical after matching.
The result. One comma-separated UTF-8 file with a byte-order mark for Excel, CRLF line endings and quotes only where RFC 4180 needs them. Every merge was checked by reading the output back with a separately written CSV reader. Nothing is uploaded.
Drop all the CSV files on Merge CSV Files at once. The page lists the columns of the merged file and the rows each file adds, then Merge downloads one CSV with a single header row. Up to 200 files and 500 MB in total are merged in the browser, without uploading anything.
Columns are matched by header name, ignoring capital letters and spaces around the name, and kept in the order they first appear. A column that only some files have is added once, and rows from files without it get an empty cell there. The plan lists the missing columns per file before you merge.
Yes. Each file's delimiter is detected on its own, from comma, semicolon, tab and pipe, so a semicolon export from European Excel merges with a comma export from Google Sheets. Files saved as Windows-1252 are read correctly too. The merged file is always comma-separated UTF-8.
Switch on Add a Source file column. The merged file then starts with a column holding the original file name on every row, which makes it easy to filter or build a pivot table by month, store or region after combining several exports.
Yes. The file starts with a UTF-8 byte-order mark by default, which tells Excel to show accents and non-Latin scripts correctly, and uses CRLF line endings as RFC 4180 describes. Excel opens at most 1,048,576 rows; use CSV Splitter if the merged file is larger.
No. Every CSV is read and merged by your own browser, and the result is created on your device. Nothing is sent to a server, which matters for customer lists, orders and other personal data. Closing the tab clears the files from memory.
Rates and rules change; check the source before you rely on a figure.
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Same job, other tools: Combine VCF Files – Join several contact exports into a single VCF for a one-step import · Combine Calendars into One – Put a work, a family and a school calendar export into a single file to import once.