What the XLSX to CSV Converter does
This converter exports every sheet of an Excel workbook (.xlsx or .xlsm) to CSV in your browser: you choose the sheets, the delimiter, UTF-8 with or without a byte order mark and the line endings, dates come out as ISO 8601 rather than as serial numbers, and formula cells export the result Excel saved - nothing is recalculated.
Excel's own Save As CSV writes only the active sheet, uses your computer's regional list separator, and until recently wrote ANSI rather than UTF-8. Doing it here gives one predictable file per sheet, or all of them in a ZIP, without the workbook leaving your device.
How to use it
- Drop the workbook (or load the example). Every worksheet is read; chart sheets are listed and skipped because they hold no cells.
- Pick the CSV format: comma for most tools, semicolon for European Excel, tab for pasting into databases. Keep the byte order mark if the CSV will be opened in Excel on Windows - without it Excel may misread accented letters.
- Choose how dates and numbers are written. ISO dates (2025-01-31) are unambiguous in every locale; numbers default to the 15 significant digits Excel displays, so 0.1+0.2 exports as 0.3 rather than 0.30000000000000004.
- Check the preview of each sheet, untick any you do not need, and download one CSV or a ZIP of all ticked sheets.
Reading the results
Formula cells are exported as the value cached in the file at its last save. If a workbook was produced by a program that never calculated it, those cells have no cached value and export empty; the notes tell you how many.
A cell counts as a date when its number format is a date or time format, exactly as Excel decides. Date-only formats export as YYYY-MM-DD, time formats as HH:MM:SS and combined formats as both. Percentages keep the stored fraction: 12.5% exports as 0.125.
Merged cells hold their value only in the top-left cell. The fill option repeats it across the merged range, which is usually what you want for a report layout and wrong for a data table - choose per workbook.
Worked example: a three-sheet sales workbook
The example workbook has Sales (12 orders), Customers (10 rows) and Budget 2025 (a formula sheet). On Sales, the Date column uses the format dd/mm/yyyy over serial numbers from 45658: 45658 is 1 January 2025 in Excel's 1900 date system (1 January 2024 is 45292, plus 366 days for the leap year), so the first order exports as 2025-01-01 and the next, 7 days later, as 2025-01-08.
The Total column is a shared formula, =E2*F2 filled down. The second order has 5 units at 249, and its cached result 1245 is what the CSV contains. On Budget 2025, the Q4 revenue per head cell is a #DIV/0! error in Excel, and it exports as the text #DIV/0! rather than as a blank that could be mistaken for zero.
The workbook also links to an external rates file; the note says so, because the exported FX value is only as fresh as the workbook's last save.
Limitations: what the result does not prove
- Values are exported as stored, not as formatted: currency symbols, thousands separators and custom number formats are not reproduced. Dates are the exception because a raw serial number is rarely what anyone wants.
- Nothing is calculated. Volatile functions such as NOW() and RAND() export the value from the last save, and external links are not refreshed.
- Only .xlsx and .xlsm (Office Open XML) are read. Legacy .xls, .xlsb and .ods files are not supported - save them as .xlsx first. Password-protected workbooks are encrypted and cannot be opened.
- Rich text, comments, colours and hidden-row status are not part of CSV and are dropped; hidden sheets are exported unless you untick them.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- RFC 4180 CSV - checked 19 Sep 2026
- ECMA-376 Office Open XML File Formats - checked 19 Sep 2026
- Microsoft - Date systems in Excel
- OWASP - CSV Injection
Frequently asked questions
How do I convert every sheet of an Excel file to separate CSV files?
Drop the workbook, leave every sheet ticked and choose Download ticked sheets (ZIP). Each sheet becomes its own CSV named after the workbook and the sheet, which is not possible with Excel's Save As, since that writes only the active sheet.
Should I choose UTF-8 with or without a BOM?
With the BOM if the CSV will be opened by double-clicking in Excel, because Excel uses it to recognise UTF-8 and otherwise may show accented letters as garbage. Without the BOM for programs and scripts, which often treat the BOM as part of the first header name.
Why do my Excel dates turn into numbers like 45658 in other converters?
Excel stores dates as the count of days since 1900 (with a historical quirk that treats 1900 as a leap year) and only the cell's format says it is a date. This converter reads the format and writes ISO dates; choose Excel serial numbers if another system expects them.
Are formulas exported or their results?
Their results - specifically the result Excel cached when the workbook was last saved. The formula text is not included in the CSV. To see the formulas themselves, use the XLSX Formula Inspector, which lists every formula by sheet and cell.
What does the formula-injection option do?
It prefixes text that starts with =, +, - or @ with an apostrophe, so that a spreadsheet opening the CSV shows it as text rather than evaluating it. It is off by default because it changes the data; turn it on when the CSV will be opened by people in Excel and the source is untrusted.
Why is a number like 0.1+0.2 exported as 0.3?
Binary floating point stores it as 0.30000000000000004, and Excel rounds what it shows to 15 significant digits. The default follows Excel so the CSV matches what you saw; choose Exactly as stored when you need the full binary value.
Last reviewed by the A2Z.Tools team against the sources listed above.
