FileGizmo — Data & CSV tools
Merge CSV files
Merge multiple CSV files into one clean dataset in your browser for free. Match or combine columns and download the result without uploading your files.
Merging your files…
Every file remains on this device.
Merge complete
Your combined file is ready
Simple by design
Merge CSV in three steps
Merging CSV files combines rows from several exports or datasets into one table. It is useful for monthly reports, survey batches, transaction exports, analytics downloads, and other files that share a similar structure. The first row of each file is treated as its column header rather than data.
FileGizmo merges every CSV locally in your browser. Select two or more files, choose how their columns should be handled, and download the combined result. Nothing is uploaded, so business records, customer data, and internal exports stay on your device.
Use union mode when files have overlapping but not identical columns. FileGizmo creates one complete header set and leaves unavailable cells empty. Use strict mode when every file must use exactly the same headers; the merge stops if a mismatch is found. Quoted commas, multiline fields, semicolon-separated data, and tab-separated files are detected automatically. Optional source labels can record which input file supplied each output row.
- 1
Select or drop two or more CSV files in the order they should be combined.
- 2
Choose whether columns must match exactly or should be combined into one complete header set.
- 3
Merge the rows, review the preview, and download the combined CSV file.
Good to know
Frequently asked questions
Is the CSV merger free?
Yes. You can merge CSV files without an account, watermarks, or artificial usage limits.
Are my CSV files uploaded?
No. Every file is read and merged locally by your browser. FileGizmo never receives the file contents.
What happens when files have different columns?
Union mode creates a complete set of columns and leaves missing cells empty. Strict mode stops and identifies files whose headers do not match the first file.
Does the order of my files matter?
Yes. Rows are appended in the order shown in the selected-file list, starting with the first file.