Excel to JSON

About the Excel to JSON

Excel to JSON reads an .xlsx worksheet and turns it into JSON. Choose which row holds the column names — or generate names — and review the final mapping from each column to its JSON key before exporting.

Blank and duplicate headers are renamed deterministically (for example “Column 3” and “email (2)”), so no value is ever overwritten. Numbers and booleans stay typed, dates become ISO 8601 strings, and formulas use the result saved in the file. Download compact or pretty-printed UTF-8 JSON.

How to use

1. Open an .xlsx workbook and choose the worksheet.
2. Choose the header row, or switch to generated column names.
3. Pick array of objects or array of rows, and how blank cells are handled.
4. Review the column-to-key mapping and warnings.
5. Choose compact or pretty-printed output and click Download JSON.

Key features

• Header row selection or generated names.
• Array of objects or array of row arrays.
• Blank cells as null or omitted properties.
• Deterministic renaming of blank and duplicate headers.
• Dates as ISO 8601 text; numbers and booleans typed.
• Warnings for renamed keys and missing formula results.

Best practices

• Use short, unique header names in the sheet.
• Use null for blanks when every object should have the same keys.
• Check the mapping table before exporting to an API.

Benefits

• Quick JSON fixtures and API payloads from spreadsheets.
• No values lost to duplicate headers.
• Private: runs offline in your browser.

Frequently asked questions