Convert an Excel file (.xlsx) to CSV locally - each sheet separately, no upload, right in your browser.
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
CSV (comma-separated values) is the simplest, most universal table format: plain text in which each line is a data row and commas separate the columns. Unlike .xlsx, CSV opens in any program - from databases to statistics tools to editors - and is ideal for import, export and scripts.
This tool reads the Excel workbook entirely locally in your browser (SheetJS, pure JavaScript) and writes one CSV per sheet. For multiple sheets you get a ZIP with all CSVs. Formulas become their computed values; formatting and charts are dropped (CSV holds values only). Nothing is uploaded.
| Input formats | XLSX |
|---|---|
| Output format | CSV |
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: Formulas are converted to values; cell formatting, charts and macros are lost (CSV stores values only). Very large workbooks need memory. Encrypted (password-protected) Excel files are not supported.
No. The conversion runs entirely locally in the browser - nothing is sent.
Each sheet becomes its own CSV; you get them all bundled as a ZIP.
CSV stores values only - formulas become their computed result.
Comma by default; the option also lets you pick semicolon or tab (e.g. for German-locale Excel or TSV).
The CSV is saved as UTF-8 without a BOM - the open standard. Older Excel on Windows, however, guesses a different encoding on double-click. Open the file via Data > From Text/CSV and pick UTF-8 instead, and umlauts and special characters come out right; LibreOffice and Google Sheets detect UTF-8 directly.