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Excel to JSON

Convert Excel .xlsx files to JSON online: pick one sheet or all, use the first row as keys and turn Excel dates into ISO dates. The file stays in your browser.

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About the Excel to JSON

The Excel to JSON Converter reads .xlsx workbooks in your browser and turns their rows into JSON: an array of objects keyed by the header row, or arrays of values. Pick one sheet or all of them, and Excel dates are converted to ISO dates such as 2026-11-09 instead of serial numbers like 46335.

Conversion happens in your browser, so your files and records stay private.

How to use the Excel to JSON

  1. Drop an .xlsx file or choose one; it is read on your device and not uploaded.
  2. Pick a sheet, or "All sheets" for an object with one array per sheet.
  3. Choose whether the first row holds the keys, whether to convert dates and whether to skip empty rows.
  4. Copy the JSON or download it as a .json file.

Common mistakes

  • Titles above the table. If the sheet starts with a title and a blank row, the title becomes the header. Empty rows at the top are skipped, but delete title rows in Excel first.
  • Numbers stored as text. Cells Excel shows with a green triangle are text, and they stay strings in the JSON. Convert them to numbers in Excel if you need numbers.

Works well with the Excel to JSON

Frequently asked questions

How are Excel dates converted?

Excel stores dates as serial numbers (days since 1900). Cells formatted as dates become ISO text: 2026-11-09 for a date, 2026-11-09T14:30:00 with a time, or 14:30:00 for a time only. Turn the option off to keep the serial numbers.

What happens to formulas?

The value Excel last calculated and saved is used, not the formula itself. Files saved by Excel, Google Sheets and LibreOffice include these values.

Can I convert old .xls files?

No, only .xlsx and .xlsm. Open an .xls file in Excel, Google Sheets or LibreOffice and save it as .xlsx first.

What if the header row has blanks or repeats?

An empty header cell uses the column letter (C) as its key, and a repeated name gets a suffix (name_2), so no column is overwritten.

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