Merge Columns in Excel Online — Free, No Upload, 1 Click

Two Modes: Keep or Remove the Source Columns

With a header row, the new column gets the header you type (or “Merged” if you leave it blank). Without a header row, every row is merged, including the first one.

How to Merge Columns Online

1. Drop one .xlsx, .xlsm, or .xls workbook — it is parsed locally in your browser and never uploaded.
2. As soon as the file is read, the first worksheet’s header row appears as a column list (A — Name, B — City…). If a header cell is empty, only the column letter is shown.
3. Tick at least two columns to merge. Values are joined in the order you tick them, using the separator you choose.
4. Set the separator (a space by default — try “, ” or “ - ”), the new column’s header, and whether to keep the source columns and treat the first row as a header.
5. Click Merge columns and download the result as your-file-name-merged-columns.xlsx.

The same column positions apply to every worksheet in the workbook — selecting A and C merges columns A and C on every sheet. Worksheets narrower than your selection are left untouched and listed as skipped.

How It Works

This tool reads your workbook in the browser with SheetJS, loading each worksheet into an in-memory array of rows. For every row it walks the columns you ticked, in the order you ticked them, and joins the cell text with your separator — empty, null, and blank-string cells are skipped, so no dangling separator appears. The merged value lands in a new column: after the last selected column when you keep the sources, or in the first selected column’s place when you remove them. Every worksheet is merged at the same column positions; sheets narrower than your selection stay untouched. The result is then rebuilt as a fresh .xlsx from cell values and downloaded — styles, merged cells, and charts are simplified, and formulas fall back to their cached values.

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

Compared to CONCATENATE Formulas

In Excel you would write =A1&" "&B1 (or =CONCATENATE(A1," ",B1)), drag-fill it down every row, then paste-as-values if you want text. This tool merges the whole column in one click and hands back a fresh file.

When You Need This

• Combine a first-name and a last-name column into one full name.
• Join street, city, and postal-code columns into a single address field.
• Build a primary key, username, or email from several columns (e.g. firstname.lastname@company.com).
• Merge an area code with a phone number, or a product category with an SKU.

Empty cells are skipped automatically — joining A, (empty), and B produces “A B” with a single separator, never “A B” or a dangling separator. Rows where every selected cell is empty get an empty merged cell.

Limitations

• The output is a value-level .xlsx rebuilt from your data: cell styles, column widths, merged cells, formulas, and charts are simplified.
• Dates are converted to text when joined — a date becomes an English date string such as “Mon Jan 15 2024 …”, not a formatted date. Format dates as text first if the exact display matters.
• Columns are picked by position (A, B, C…) from the first worksheet; different sheets cannot use different columns.
• Encrypted workbooks cannot be read. Legacy .xls files are accepted but delivered as .xlsx.