Excel to CSV Converter
Convert XLSX to CSV by parsing Office Open XML via JSZip in your browser. Handles shared strings, numbers, booleans, and date serials.
Excel to CSV Converter
Convert XLSX spreadsheets to CSV by parsing the Office Open XML structure directly in your browser. No data leaves your machine.
Upload XLSX File
Click to upload an .xlsx file
Only .xlsx files are supported
Options
How it works
Real XLSX parsing: XLSX files are ZIP archives containing XML. This tool uses JSZip to unpack the archive, then reads xl/sharedStrings.xml for text values and xl/worksheets/sheet1.xml for cell data.
Cell types: Shared string references, inline strings, numbers, booleans, and date serials (converted to ISO 8601 format) are all handled.
Privacy: All processing happens in your browser. No spreadsheet data is uploaded to any server.
Frequently Asked Questions
What is the 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.
How without a library?
XLSX = ZIP of XML. JSZip extracts it, then the tool reads sharedStrings.xml + sheet1.xml for cell data.
Dates?
Excel stores dates as serial numbers. The tool detects date-formatted cells and converts to ISO 8601.
Data uploaded?
No. All parsing in your browser.
Is the Excel to CSV Converter free to use?
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.
Does the Excel to CSV Converter work on mobile devices?
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.
Do I need to create an account to use this tool?
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.
How do I use the Excel to CSV Converter?
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.
Which browsers are supported?
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.
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About Excel to CSV Converter
Excel to CSV Converter is a free, browser-based tool in our Converter Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.