Merge Excel files online
Combine multiple .xlsx and .csv files into one spreadsheet — in seconds, 100% in your browser. Your files never leave your device.
Free up to 3 files Columns aligned by name No upload, no account
Drag & drop files here
.xlsx, .xls, .csv — drop 2 or more
How to merge Excel files online
- Drop your files
Add 2 or more .xlsx, .xls, or .csv files. Mix formats freely.
- Choose a mode
Append rows stacks all data into one sheet, aligning columns by header name. Combine into sheets puts each file on its own tab.
- Preview & download
Review the merged table, then download your clean .xlsx file.
Frequently asked questions
- How do I merge Excel files online?
- Drop your .xlsx or .csv files into the tool above and choose Append rows. SheetToolkit merges them instantly in your browser — no upload, no account needed.
- How do I merge multiple Excel files into one sheet?
- Use Append rows mode. SheetToolkit stacks every row from every file into a single sheet, matching columns by header name. Columns missing in some files are left blank — no data is lost.
- What if my files have columns in a different order?
- SheetToolkit aligns columns by their header names, not by position. If file A has "ID, Name, Amount" and file B has "Amount, ID, Name", the output will still have them in the correct columns.
- Can I merge CSV files with Excel files?
- Yes. SheetToolkit accepts .xlsx, .xls, and .csv files in any combination. The merged output is always a clean .xlsx file.
- Is my data private?
- Completely. All processing happens in your browser using JavaScript. Your files are never uploaded to any server. You can even use SheetToolkit offline after the page loads.
- What is the free row limit?
- Free users can merge up to 3 files and 5,000 rows total. For larger datasets, SheetToolkit Pro removes all limits with a one-time payment.