The problem with many small files
Data often arrives in pieces: one spreadsheet per month, per team, or per export. To analyse it, you usually need it all in one place. Copying and pasting by hand is slow and easy to get wrong — you can miss a file, misalign a column, or paste over something. Merging does it cleanly in one step.
Two ways to merge
The Merge Excel & CSV tool gives you two clear options:
- Stack into one sheet. Every row from every file goes into a single sheet, one under another. This is what you want for analysis, sorting, and totals.
- One sheet per file. Each file becomes its own tab in a single workbook. This keeps the sources separate but in one convenient file.
Lining up the columns
Real files are messy. One export might list columns as Name, Email, City, and another as Email, Name, Country. The tool has an option called align columns by header. When it is on, columns with the same header line up automatically, even if they are in a different order or some files have extra columns. Leave this on unless your files have no headers at all.
Step by step
- Open the Merge Excel & CSV tool.
- Add all the Excel and CSV files you want to combine.
- Choose "stack into one sheet" or "one sheet per file".
- Keep "align columns by header" on so columns match up.
- Download the merged Excel or CSV file.
Know where each row came from
When you stack many files together, it is easy to lose track of which file a row came from. Turn on the Source File column and the tool adds a column showing the original file name for every row. This is very handy for checking your data later.
Is my data private?
Yes. Merge Excel & CSV runs inside your browser. Your spreadsheets are read and combined on your own device, and nothing is uploaded to a server. Sales figures, customer lists, and payroll data all stay private.
Tips for a clean merge
- Match your headers first. If the same thing is called "Email" in one file and "E-mail" in another, they will not line up. Make headers match where you can.
- Mixed formats are fine. You can add Excel and CSV files together in the same merge.
- Clean up after. After merging, you often want to remove duplicate rows, since the same record may appear in more than one file.
- Too big to send? If the merged file is huge, Split Excel can break it into smaller pieces.
A quick example
You have 12 monthly sales files and want one file for the year. Open Merge Excel & CSV, add all 12, choose "stack into one sheet", keep "align columns by header" on, and turn on the Source File column. Download one workbook with every sale for the year in a single sheet — ready to sort, total, or chart.
Try it now — free and private
Ready to combine your sheets? Open the Merge Excel & CSV tool, add your files, and download one workbook.