Key Features
- Merge CSV files with different headers or different columns into one file
- Map each source column to the target column (or leave it out), so mismatched files line up
- Keep the union of fields, or only the columns you select
- Append rows from many CSV files, in the order you choose
- Batch merge a whole folder, with recursive folder scanning
- 100% local processing, no data sent to the cloud
- Windows, macOS and Linux, GUI wizard and command line (CLI)
- Save sessions and automate with Windows Task Scheduler or crontab
- Fast on large files with millions of rows
Same Header or Different Headers?
Pick the tool that matches your files, so the merge stays simple and predictable:
| Your files | What to use |
|---|---|
| Same header / same columns (plain concatenation) | Merge CSV files with the same header — the lightweight TextMerger, which keeps one header row |
| Different headers / different columns | DataFileConverter (this page) — map and align columns, keep the union of fields |
How to Merge CSV Files with Different Columns (GUI Steps)
- Launch DataFileConverter, start a new task and set source/target type to CSV 📷
- Add the CSV files (or a folder) that have different headers 📷
- Map the columns: match each source field to the target column, or leave a field out 📷
- Set the output CSV and run the merge, then preview the result 📷
Example: two files, different columns
customers_1.csv: id,name,email
customers_2.csv: id,name,phone,country
Merged output: id,name,email,phone,country
(missing values are left empty for the file that lacks the column)
Command Line Automation
You can merge CSV files with a different schema from the command line:
- Build the merge in the GUI and save the session
- Generate a .bat (Windows) or .sh (macOS/Linux) script 📷
- Run it in the command prompt or terminal
- Schedule it with Windows Task Scheduler or crontab
Frequently Asked Questions
A: Yes. Add all the CSV files, then map each source column to the matching target column. Columns that a file does not have are simply left empty in the merged output.
A: Yes. The result is one CSV file with a single header; the union of columns from all input files is used, in the order you set.
A: If every file has the same header, use the same-header CSV merger (TextMerger). When the headers differ, use DataFileConverter to map and align the columns before merging.
A: Yes. All operations run locally on your computer. No files are uploaded to any server.
A: Yes. Native versions are available for Windows, macOS and Linux, with GUI and command line.
A: Yes. You can select an entire folder (recursively) and merge all CSV files in one run.
Related Tools
- Merge CSV files with the same header (TextMerger)
- Merge JSON files
- Convert CSV to JSON
- Merge text files into one CSV
- All CSV tools
Merge Your CSV Files Today
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