Excel to CSV Converter

The Excel to CSV Converter is a free online tool that convert xlsx to csv by parsing office open xml via jszip in your browser. handles shared strings, numbers, booleans, and date serials.. It runs entirely in your browser with no installation or sign-up needed.

XLSX = ZIP of XML. JSZip extracts it, then the tool reads sharedStrings.xml + sheet1.xml for cell data.

Excel stores dates as serial numbers. The tool detects date-formatted cells and converts to ISO 8601.

No. All parsing in your browser.

Yes, the Excel to CSV Converter is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.

Yes, the Excel to CSV Converter is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Excel to CSV Converter in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Excel to CSV Converter works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

XLSX is Microsoft Excel's modern format: a ZIP archive of XML files that stores not just cell values but also formulas, multiple worksheets, formatting, number styles, charts, and merged cells. CSV is a plain-text file where each line is one row and values are separated by a delimiter, usually a comma. CSV holds only the raw data, so it loses formulas, colors, fonts, and any layout, but it is universally readable by databases, scripts, and data tools that cannot open a binary-style spreadsheet. Converting XLSX to CSV flattens one worksheet into that simple grid: text, numbers, booleans, and dates remain, while everything visual is stripped away. This tool reads the real XLSX structure and rebuilds the first sheet as clean CSV, so you can move spreadsheet data into systems that only accept comma-separated values. Upload a file above to convert it instantly.

Yes. The delimiter setting lets you choose a comma, a semicolon, or a tab, which covers the cases where a plain comma causes trouble. Semicolons matter in many European locales, where the comma is used as the decimal separator and a comma-delimited file would split numbers incorrectly; switching to semicolons keeps those values intact. Tabs are useful when your data already contains commas or semicolons inside fields, since tabs rarely appear in text. When you pick the tab delimiter, the converter saves the download as a .tsv file, while comma and semicolon outputs are saved as .csv. Whichever delimiter you choose, fields that contain that character, a quote, or a line break are wrapped in double quotes following the RFC 4180 convention, so the file imports cleanly. Choose your delimiter in the options panel before copying or downloading.

A CSV file is a single flat table by design, so it has no way to represent more than one worksheet. This converter reads only the first worksheet of your workbook, the one stored as sheet1.xml inside the XLSX archive, and turns that into CSV. Any data on later tabs is ignored, which is why a multi-sheet workbook produces a single-sheet result. If the data you need lives on a second or third tab, open the file in your spreadsheet program first, move or copy that sheet so it becomes the first one, save, and then convert. Treating the first row as your headers, the tool rebuilds the grid from that one sheet exactly as it appears. After uploading, check the row and column counts and the preview to confirm you are looking at the right worksheet before you download.

Excel does not store dates as text; it stores them as serial numbers counting the days since the end of 1899, then displays them using a number format. This tool reads each cell's format and, when the format is a date style, converts the serial number back into a readable ISO 8601 date in YYYY-MM-DD form, which sorts correctly and is unambiguous across regions. It also corrects a long-standing quirk: Excel wrongly treats 1900 as a leap year and includes a non-existent 29 February 1900, which shifts every serial after that point by one day. The converter compensates for this for serials past day 60, so dates after 28 February 1900 land on the correct calendar day. Plain numbers without a date format are written through unchanged, with no rounding or reformatting. Upload your spreadsheet and check the preview to confirm dates appear as expected.

This converter supports only the modern .xlsx format, which is an Office Open XML package: a ZIP archive containing XML parts that the tool unpacks and reads directly. The older .xls format is a completely different binary structure left over from earlier Excel versions, so it cannot be parsed the same way and will not load. Macro-enabled .xlsm files and other variants are also outside its scope. The fix is simple: open the file in Excel, LibreOffice Calc, or Google Sheets, then use Save As or Export and choose the .xlsx (Excel Workbook) format. Converting to .xlsx discards any macros but keeps your actual cell data intact, which is all a CSV needs. Once you have a true .xlsx file, upload it here and the tool will rebuild the first worksheet, resolve shared strings, numbers, booleans, and dates, and give you a clean CSV to copy or download.