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Append Excel files as rows beneath one header

Append Excel files when exports share the same columns and you want one longer table, not a join by ID. This mode stacks first-sheet data rows beneath a single header in a new Merged worksheet.

Select at least two files. The tool keeps the first input header and skips the first row of every later file. It does not match columns by name, sort records or remove duplicates, so preparing the same layout in every file is essential.

Combine your XLSX files

Ready. Input stays in your browser. Limit: 20 MB per file or pasted input.

How to append excel files

  1. Make the first sheet of each .xlsx file a rectangular table with its header on row one. Each file must be 20 MB or smaller.
  2. Compare headers exactly, including capitalization, spaces and column order. Correct mismatches in the source files before trying to append.
  3. Choose at least two files and keep Append first-sheet rows selected. Data follows the file-input order, with each file retaining its row order.
  4. Select Merge to XLSX, download merged.xlsx and inspect the Merged sheet. If a particular sequence matters, verify it in the output because there is no file-reordering control.

Need other source tabs? Split a workbook into single-sheet XLSX files before merging them.

Example input and output

First file:
id | amount
A1 | 10

Second file:
id | amount
A1 | 10
A2 | 20

Merged output:
id | amount
A1 | 10
A1 | 10
A2 | 20

The repeated A1 record remains. A header of amount | id would be rejected.

Limitations to check first

Append mode reads only the first sheet of each file. Only .xlsx is supported, with a 20 MB limit per file. Headers must match exactly; extra columns or reordered headers are rejected, not automatically reconciled. The result must fit Excel worksheet limits, and large batches can exhaust browser memory.

Practical tips

Do not use append for side-by-side comparisons or key-based reconciliation. If exports lack a source column, add one before merging so you can trace rows afterward. Formulas become cached values and formatting and charts are not preserved; keep the original workbooks.

Frequently asked questions

Does append combine rows or join columns?

It combines rows vertically into one Merged worksheet. It does not join tables on an ID, align differently ordered columns or add a source-filename column.

Why is a header mismatch rejected?

Append requires exactly matching first rows in the same column order. Check capitalization, whitespace, extra columns and leading title rows in the first sheet of every file.

Will duplicate rows be removed?

No. Duplicate data rows are kept. Only the first row of later files is skipped after its header has been checked against the first file.

Which sheets and file order are used?

Only the first sheet of each file is read. Files follow the order supplied by the file input, and rows retain their source order. There is no reordering control, so inspect the output if sequence matters.

Are uploads required and what limits apply?

No. Files are not uploaded; merging runs locally in your browser. Choose at least two XLSX files, each 20 MB or smaller. Excel worksheet limits and browser memory also constrain the combined result.

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