How to use
Drop the Excel (.xlsx), CSV or TSV files to combine, or add them with “Choose files”. Excel and CSV can be mixed.
Each file lists its sheets. Tick the sheets to include and check the header row (it is detected even below a title). Drag the handle to change the order.
Choose how to combine: “Stack rows” for monthly or per-branch tables, “Sheets into one workbook” to keep sheets separate in one file, or “Join by key column” to place tables side by side.
When stacking, adjust order, names and inclusion under “Output columns”, and combine differently named columns (Amount / Sales amount) with “Merge into”.
Check the preview and notices (mismatched data types, duplicate headers…), then download as Excel or CSV.
What it does
Stacks rows with columns aligned by header
Even when column order differs between files, rows are appended into matching columns by header name. Headers that differ only in width or spacing count as the same column, and missing columns are left blank. An overview shows which sheet has which column.
Merge renamed columns and tailor the output
Combine columns with different names, such as “Amount” and “Sales amount”, into one. Reorder columns (drag or keyboard), rename them or leave them out while watching the result.
Handles titles, empty rows and repeated headers
The header row is detected even when a title or date line sits above the table (and can be changed per sheet). Empty rows and repeated header rows from pasted tables can be dropped, and columns with the source file, sheet and row number can be added.
Workbook output that follows Excel’s sheet-name rules
When each sheet becomes its own sheet in one workbook, the 31-character limit, forbidden characters and duplicate names are handled automatically. Names come from the sheet, the file, or “file_sheet”, and can be edited individually.
Key joins: left, inner and full outer
Place two or more tables side by side using a shared column such as an employee ID or product code. Spacing, width and case differences in keys can be ignored, and unmatched rows and duplicate keys are counted.
Warns about inconsistent data
You are told when a column holds numbers in one sheet and text in another, or when a sheet has duplicate headers. Digit-only text from CSV such as “1200” can become numbers, while codes with a leading zero stay text.
Use cases
- Combine sales tables split by branch or month into one table for totals or a pivot table
- Merge the same template collected from several people into one file
- Join several Shift_JIS CSV files into one file that opens correctly in Excel
- Put scattered Excel files into one workbook with tidy sheet names
- Add columns from another table by a shared ID without VLOOKUP
Supported formats
Input
Output
Capability matrix
| Feature | Support | Notes |
|---|---|---|
| Stack rows from many files/sheets, columns aligned by header | Supported | — |
| Merge renamed columns, reorder, rename, exclude columns | Supported | — |
| Header row detection (skips titles) | Supported | Adjustable per sheet |
| Put each sheet into one workbook | Supported | Names kept within 31 characters and unique |
| Join by key column (left, inner, full outer) | Partial | One key column per sheet; no multi-column or fuzzy keys |
| Warnings for mixed data types and duplicate headers | Supported | — |
| Keep formatting, formulas, merged cells, charts | Not supported | Values only (formulas become their results) |
| Legacy Excel (.xls) | Not supported | Re-save as .xlsx in Excel first |
Limits & notes
- Up to 50 files and 200 sheets at once; up to 100 MB and 3 million cells per file.
- The combined result can have up to 3 million cells.
- Only cell values are combined. Formatting (colours, borders), formulas (they become their results), merged cells, charts and data validation are not carried over.
- The header row can be chosen from the first 30 rows.
- In key joins, keys that appear on several rows produce one row per matching combination (like a database join).
Privacy & safety
Reading, combining and building the download all happen in your browser. File contents are never sent to or stored on a server.
FAQ
How do I combine several Excel files into one?
Can I merge files whose column order or names differ?
Can I tell which file each row came from?
Can I mix CSV and Excel files?
Can I add columns from another table like VLOOKUP?
Are my files uploaded?
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