XLSX to CSV Converter — Fast & Free Online

Converting XLSX to CSV extracts the cell values from a spreadsheet and writes them as plain comma-separated text, making the data importable into any database, analytics tool, or programming environment that reads CSV. XLSX is the XML-based Office Open XML spreadsheet format used by Microsoft Excel, storing cell values, formulas, formatting, charts, and pivot tables in a zipped XML structure. CSV stores only the raw cell values as delimited plain text — one row per line, fields separated by commas (or semicolons in some regional settings). Formulas are evaluated and their computed values are written to the CSV; charts, conditional formatting, and cell styles are discarded. Each worksheet in a multi-sheet workbook can be exported as a separate CSV file. The output encoding is UTF-8 by default, preserving Unicode characters in cell values. 1converter uses LibreOffice Calc in headless mode to evaluate formulas and export the active sheet or all sheets to CSV.