TSV to XLSX

real .xlsx workbook · named sheet · nothing uploaded

Produce a genuine Excel workbook from tab-separated data — not a CSV with the extension changed. That distinction matters when you hand a file to someone who'll double-click it: a real .xlsx opens without an import dialog, without a "this file's format doesn't match its extension" warning, and without Excel guessing at your delimiter. The reverse trip is Excel → TSV.

How to use

1. Paste or drop the TSV. The status line reports the row and column count it will write.
2. Name the sheet if Sheet1 isn't what you want — Excel caps sheet names at 31 characters.
3. Click Download .xlsx. There's no preview pane here because a workbook isn't text.

What Excel will do to your data anyway

The workbook is written with all values as text, which is the safe choice — but Excel applies its own display logic when you open it, and there are two behaviours worth knowing. Values that look like dates may be shown as dates, and long digit strings may be displayed in scientific notation. Formatting a column as Text in Excel before typing into it is the only durable fix; nothing in the file can prevent it.

That asymmetry is the reason to keep the TSV as your source of truth and treat the workbook as a delivery format. If someone sends the workbook back, Excel → TSV converts it, and TSV diff shows you what they changed.

Why this page needs the network

Writing the Open XML format means building a zip of XML parts. That's done here by SheetJS, loaded from a CDN with a subresource-integrity hash — so the code is verified before it runs, and your data still never leaves the browser. This is one of only two pages on the site with an external dependency; the rest work fully offline.

FAQ

Privacy

100% client-side. No upload. See the privacy policy.