Free, secure Excel converter
Free, secure Excel converter. Convert XLSX to CSV or JSON in your browser—files never leave your device. This free, secure Excel converter runs entirely in your
browser—no account required and no watermarks on your output.
Convert XLSX to CSV for spreadsheets and databases, or XLSX to JSON for
APIs and apps. Optionally pick a worksheet by name. Every operation stays
on your device.
How it works
- Upload an XLSX file using the drop zone or file picker.
- Choose CSV or JSON as the output format. Optionally specify a sheet name.
- Click Convert, then download your result. Nothing is uploaded to a server.
Supported Excel conversions
- XLSX → CSV
— Convert Excel (XLSX) to CSV with optional sheet selection. Defaults to the first worksheet.
- XLSX → JSON
— Convert Excel (XLSX) to JSON with optional sheet selection. Rows become objects keyed by column headers.
Secure and private
Your spreadsheets are processed locally in your browser. Nothing is stored on a server and nothing is uploaded over the network. That makes this tool a good fit for financial data, HR exports, and other sensitive workbooks you do not want to send to a third-party service.
Frequently asked questions
Is this Excel converter free?
Yes. Every conversion is free with no account, watermark, or usage limit.
Is this Excel converter secure?
Yes. Files are processed locally in your browser. Nothing is uploaded to a server, so your spreadsheets stay on your device.
What formats can I convert XLSX to?
You can convert XLSX (Excel) files to CSV or JSON. Both options support an optional sheet name; if omitted, the first worksheet is used.
Can I choose which worksheet to convert?
Yes. Enter a sheet name in the options before converting. If you leave it blank, the converter uses the first sheet in the workbook.
Does the converter work on mobile?
Yes. It runs in modern mobile browsers that support HTML5 and JavaScript. Very large files may be slower on mobile devices.
What is the maximum file size?
Each file can be up to about 50 MB. If a file is too large, you will see a clear error message asking you to use a smaller file.
Why did my conversion fail?
Common causes are a non-XLSX file, corrupted workbook data, or exceeding the size limit. Check the message below the converter for specific guidance, then try again or refresh the page.
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