How does each row become a JSON object?

The first row is treated as the header, and each cell in every row below it becomes a key/value pair using that header as the key — so a sheet with columns Name, Email, and Age produces an array of objects like { "Name": "...", "Email": "...", "Age": ... }, one object per row.

What happens to empty cells?

Empty cells become empty strings in the output rather than being omitted, so every row object has the same consistent set of keys — this matters if you're feeding the JSON into code that expects every object to have the same shape.

Does this handle numbers, dates, and formulas correctly?

Numbers come through as JSON numbers. Dates and formulas are converted to their currently displayed/calculated value, since JSON has no native date type and can't store a live formula — if you need the raw formula text, you'll need to open the workbook directly.

Is my spreadsheet uploaded to a server?

No — the workbook is parsed entirely in your browser tab using a JavaScript spreadsheet library. Nothing is uploaded, which matters if the sheet contains financial data, customer records, or anything else you'd rather not send anywhere.

XLSX TO JSON CONVERTER

Convert an Excel sheet into a JSON array of row objects, keyed by the header row.

Drop an .xlsx or .xls file here or click to browse

Nothing is uploaded — the workbook is read right in your browser tab.

How to convert XLSX to JSON

1
Drop an .xlsx or .xls file, or click to browse.
2
If the workbook has multiple sheets, pick the one you want converted.
3
Review the generated JSON array, then copy it or download it as a .json file.

Questions

How does each row become a JSON object?: The first row is treated as the header, and each cell in every row below it becomes a key/value pair using that header as the key — so a sheet with columns Name, Email, and Age produces an array of objects like { "Name": "...", "Email": "...", "Age": ... }, one object per row.
What happens to empty cells?: Empty cells become empty strings in the output rather than being omitted, so every row object has the same consistent set of keys — this matters if you're feeding the JSON into code that expects every object to have the same shape.
Does this handle numbers, dates, and formulas correctly?: Numbers come through as JSON numbers. Dates and formulas are converted to their currently displayed/calculated value, since JSON has no native date type and can't store a live formula — if you need the raw formula text, you'll need to open the workbook directly.
Is my spreadsheet uploaded to a server?: No — the workbook is parsed entirely in your browser tab using a JavaScript spreadsheet library. Nothing is uploaded, which matters if the sheet contains financial data, customer records, or anything else you'd rather not send anywhere.