Use strict mode for repeated exports that should contain the same fields. Choose union mode when a newer export adds or removes columns. The merger keeps every row in file order and fills unavailable union columns with empty cells.
Private browser utility / Developer
Free CSV Merger
Runs entirely in your browser - no upload, no sign-up.
CSV files
Add two or more files, then set their merge order.
Drop CSV files hereCSV, TSV, or text files. Up to 25 files and 10 MB combined.
Cmd or Ctrl + Enter
What is a CSV merger?
A CSV merger combines rows from multiple CSV files into one table with a single header. This tool aligns columns by name, preserves the order of your files and rows, previews the result, and creates a clean download entirely in your browser. Your source files are never uploaded.
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How to use
- 01Add CSV files
Choose or drop at least two CSV, TSV, or text files. Each file must have a header row.
- 02Set the row order
Move files up or down. Rows from the first file appear first in the output.
- 03Choose column handling
Require matching columns for a consistent schema, or use union mode to keep every unique heading.
- 04Merge and export
Review the merged preview, then copy the CSV or download the complete UTF-8 file.
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Who it's for
- Analysts combining monthly sales, finance, or operations exports into one reporting table.
- Researchers stacking survey waves or field-team files before analysis.
- Marketing and support teams consolidating regional contact or ticket exports with evolving columns.
- Developers reassembling split CSV data while preserving quoted commas, line breaks, and leading zeros.
FAQ
Are my CSV files uploaded?
No. The files are read and merged by JavaScript in your browser. Their contents are not sent to CanDoYa for processing. Keep the tab open until you download the result because the workspace is not stored on a server.
Is the CSV merger free?
Yes. You can merge, preview, copy, and download CSV data without creating an account or installing software. The practical limits protect browser responsiveness: up to 25 files, 10 MB of input, 100,000 data rows, and 500 output columns per merge.
How many CSV files can I combine?
You can combine between 2 and 25 files in one workspace, with a combined input size of up to 10 MB. For a larger collection, merge it in smaller groups and then merge those outputs, provided the final result stays within the row and column limits.
Can I merge CSV files with different columns?
Yes. Union mode keeps every unique header in the order it first appears and inserts empty cells where a file lacks that column. Strict mode instead requires the same set of headers in every file, although their source order may differ.
Does this tool join CSV files by ID?
No. It appends rows vertically and does not match records by an ID, email, or other key. If the same customer appears in two files, both rows remain. Use a key-based join or deduplication step when you need one combined record per entity.
Will quoted commas and line breaks be preserved?
Yes. The parser handles quoted commas, embedded line breaks, doubled quotation marks, Unicode text, and empty cells. The exported CSV uses comma separators, CRLF line endings, and a UTF-8 byte order mark for broad spreadsheet compatibility.