Merge multiple CSV files into one.
Combine two or more CSV or Excel files into a single spreadsheet. Edit the merged result, clean duplicates, and export — all in your browser.
How it works
Three simple steps
Open your first file
Load a CSV or Excel file into the editor to start.
Add more files
Use the merge tool to add additional CSV or Excel files to the workspace.
Export merged file
Download the combined spreadsheet as CSV, Excel, or JSON.
Key features
Everything you need
Combine multiple files
Merge rows from two or more CSV or Excel files into a single dataset.
Automatic column alignment
Columns are matched by header name so data lines up correctly.
Edit after merging
Review and edit the merged result before exporting.
No uploads
All merging happens in your browser. Your files stay on your device.
Your data stays on your device
SheetTool processes everything locally in your browser. Your files are never uploaded to a server. No account required.
FAQ
Frequently asked questions
How do I merge CSV files?
Open the first file in SheetTool, then use the merge tool to add more files. Rows from all files are combined into one editable spreadsheet.
Can I merge CSV and Excel files together?
Yes. You can combine CSV, XLSX, and XLS files in any mix.
What happens if columns don't match?
SheetTool aligns columns by header name. Missing columns in some files will appear as empty cells in the merged result.
Is the merge tool free?
Yes. SheetTool is completely free with no sign-up required.
Ready to get started?
Open SheetTool and start working with your files right away. No sign-up needed.