Merge Excel Sheets into One Online — Free, No Upload, 1 Click

How to Merge Multiple Sheets into One Sheet Online

1. Drop one .xlsx, .xlsm, or .xls workbook containing the sheets to stack — it is processed locally and never uploaded.
2. Keep “First row is a header” enabled (the default) when each sheet starts with column names; disable it for raw row data.
3. Keep “Align columns by headers” enabled when sheets put the same columns in different orders; disable it to stack strictly by position.
4. Optionally enable “Add source sheet column” to tag every output row with the name of the sheet it came from.
5. Click Merge sheets, review the per-sheet row report, and download your-file-name-merged.xlsx.

How It Works

This tool reads your .xlsx, .xlsm, or .xls workbook directly in the browser with SheetJS, loading every worksheet into an in-memory array of rows. It then stacks the data rows of all sheets vertically into one new sheet. In header mode, the first sheet with data defines the column order; later sheets are mapped by their header text after trimming surrounding spaces, so columns land under the same heading regardless of original position — unknown columns are dropped and missing base columns are filled with empty cells. With header alignment off, rows are stacked purely by position, the output width is the widest sheet, and only one header row (from the first sheet) is emitted. Completely empty sheets and internal editor sheets whose names start with “_” are skipped automatically. The merged result is rebuilt as a value-level .xlsx — styles, column widths, merged cells, and charts are simplified, and formulas become their cached values — then packaged for download. The whole pipeline runs locally and instantly; the workbook never leaves your device.

Your file never leaves your device — processing is 100% in-browser.

Aligning Columns by Header Names

With header alignment on, the first sheet that contains data defines the column order of the result. Every later sheet is read by its header text, so columns land under the same heading regardless of their original position. The example below shows two monthly sheets whose Id and Name columns are swapped.

Header names must match exactly after trimming surrounding spaces: “ Id ” aligns with “Id”, but “ID” or “Id ” differences beyond trimming, extra punctuation, and translated names do not. Columns a sheet has but the base header does not know are dropped; base columns a sheet lacks are filled with empty cells.

Position Mode: Stack by Column Order

When header alignment is off (or the workbook has no header row at all), rows are stacked purely by position: column A under column A, column B under column B. The output width is the widest sheet, and missing positions are filled with empty cells. Only one header row is emitted in header mode — taken from the first sheet.

When You Need This

• Monthly or quarterly sheets (January…December) that share a template and must become one yearly table.
• Consolidating regional, team, or store sheets exported with the same columns before analysis or import.
• Combining several worksheets into one flat table right before uploading to a CRM, BI tool, or database.
• Turning a workbook full of similarly structured tabs into a single sheet for filtering, pivoting, or deduping afterwards.

This tool stacks sheets inside one file into one sheet. To combine several Excel files into one workbook while keeping each file’s sheets as separate tabs, use the Merge Excel files tool instead.

Good to Know Before You Merge

• The output is a value-level .xlsx rebuilt from the data: cell styles, column widths, merged cells, charts, and formulas (saved as cached values) are simplified.
• Rows are never compared or removed — identical rows from different sheets are all kept; run the duplicate remover afterwards if needed.
• Completely empty sheets are skipped automatically, and internal editor sheets (names starting with “_”) are ignored.
• Encrypted workbooks cannot be read; legacy .xls files are accepted but the result is always written as .xlsx.