Your files never leave this device — 100% in-browser

Excel to CSV Converter

Workbook in, clean machine-readable CSV out — converted on your device, never uploaded.

Drop an .xlsx or .xls workbook and get a clean UTF-8 CSV of its first sheet — values as Excel displays them, cells quoted per RFC 4180, BOM and CRLF included so the file round-trips back into Excel without mangling 한글 or accents. Spreadsheets with customer data never touch a server.

Last verified 2026-08-15 — this tool passed 85 automated end-to-end checks

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Drop an .xlsx / .xls file here, or click to browse

converts to CSV · first sheet · displayed values · UTF-8 BOM

01 — WHAT YOU SEE IS WHAT EXPORTS

Cells export as Excel displays them — dates and formatted numbers come out as their visible text, not raw serial numbers.

02 — CLEAN QUOTING

Commas, quotes and line breaks inside cells are quoted per RFC 4180 — the output parses correctly everywhere.

03 — PRIVATE

The spreadsheets people convert are payrolls and customer lists. The workbook is read entirely in your browser.

How to use

Drop your file(s) into the box above — or click it to browse.
Conversion starts immediately — no settings needed.
Click Download on each finished file — or Download all (.zip) for a batch. Nothing was uploaded at any point.

Why exports go through CSV at all

CSV is the lingua franca that imports everywhere xlsx doesn't: databases, scripts, CRMs, mailing tools, government portals. The failure modes of a bad export are well known — dates turning into serial numbers like 45123, commas inside addresses shredding columns, Korean text turning to mojibake in Excel re-import. This converter addresses each: values export as displayed (formatted dates stay dates), quoting follows RFC 4180, and the output carries a UTF-8 BOM with CRLF endings — the exact combination Excel itself needs to reopen the file correctly.

v1 exports the first sheet and tells you when a workbook has more; per-sheet selection is on the roadmap.

Export behavior
Property	Behavior
Sheet	First sheet (count of others reported)
Values	As displayed — formatted dates/numbers as text
Quoting	RFC 4180 (commas, quotes, line breaks)
Encoding	UTF-8 with BOM, CRLF endings
Inputs	.xlsx and legacy .xls

When NOT to convert

Formulas matter — CSV stores results, not formulas; the calculation logic stays behind.
Styling, merges, multiple sheets — CSV is one flat table; complex workbooks lose structure by definition.
The recipient accepts xlsx — skip the conversion and keep types intact.

Frequently asked questions

My workbook has several sheets — which one exports?

The first sheet; the status line reports how many sheets exist so nothing is silently ignored. Per-sheet choice is planned.

Why do dates come out as text like "2026-08-16"?

Deliberately — the export uses displayed values, so you get readable dates instead of Excel's internal serial numbers like 46248.

Is the workbook uploaded?

No — it is parsed in your browser by SheetJS (open source, Apache-2.0). The network tab shows zero upload traffic.