Excel to CSV Converter
Convert .xlsx and .xls workbooks to CSV — one CSV per sheet, bundled into a ZIP.
Quick answer: Excel to CSV Converter: convert .xlsx and .xls workbooks to CSV — one CSV per sheet, bundled into a ZIP. Runs entirely in your browser, free, no signup.
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CSV is the lowest common denominator that every database importer, data pipeline, and scripting language reads without a fuss, which is why exporting a workbook to CSV is often the first step in getting spreadsheet data into another system. Each sheet becomes its own file — a single-sheet workbook downloads as one .csv, while a multi-sheet workbook bundles into a ZIP with one CSV per tab, so you never silently lose the sheets you can't see.
The conversion flattens everything a spreadsheet layers on top of raw values. Formulas are exported as their computed result, not the formula text; colors, borders, and bold are gone; and merged cells expand to repeated values so the output is a clean rectangle. That last behavior is what keeps downstream parsers happy — a ragged grid with holes breaks most CSV readers.
Dates are the classic pain point in Excel exports because of locale ambiguity (is 03/04 March 4th or April 3rd?). This tool writes dates as ISO 8601 (YYYY-MM-DD), which re-imports cleanly everywhere and sorts correctly as text. If a date column comes out as a serial number instead, format that column as a real date in Excel before exporting.
If you need the trip the other way, the CSV to Excel converter rebuilds a workbook from one or more CSVs, and the delimiter converter handles the semicolon-separated variant that some European Excel locales default to.
Frequently asked questions
- Will my formulas survive?
- No — CSV has no formula concept. We export the current value of each formula cell, which is what every other Excel-to-CSV tool does too.
- What about formatting (colours, borders, bold)?
- CSV is a plain-text format and has no styling. Visual formatting is dropped; values are preserved exactly.
- How are dates exported?
- As ISO 8601 (YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS) — the format Excel imports back cleanly without locale ambiguity.
- Are my files uploaded?
- No — SheetJS runs entirely in your browser. Even confidential financial data is safe.
- What about merged cells?
- Merged cells expand to repeated values across the merge range, so the resulting CSV is rectangular and works in every downstream tool.