How to use
- Choose or drop an .xlsx, .xls, .ods or CSV file.
- Pick the sheet. Leave "First row is the header" on to get objects, or turn it off for arrays.
- Download the .json file or copy the result.
Options explained
- JSON (objects)
- An array with one object per row: [{"Name": "Ada", "Age": 36}]. Empty or repeated header cells get unique keys such as column3 or id_2.
- JSON (rows)
- An array of arrays, one per row, including the header: [["Name", "Age"], ["Ada", 36]]. Useful when the sheet has no header row.
- Types
- Numbers and booleans stay numbers and booleans; empty cells become null; dates become "2024-01-15" or "2024-01-15T09:30:00".
Example: how rows turn into JSON
With the header row switched on, the first row gives the keys and every following row becomes an object. A sheet like this:
| name | age | city | active |
|---|---|---|---|
| Ada | 36 | ||
| Bob | Rome | TRUE |
gives this JSON, where numbers and booleans keep their type and empty cells are null:
[
{"name": "Ada", "age": 36, "city": null, "active": null},
{"name": "Bob", "age": null, "city": "Rome", "active": true}
]With the header row switched off, or with the rows format, you get an array of arrays that includes the first row. Rows that are longer than the header get keys named column5, column6 and so on.
Frequently asked questions
Can I convert all sheets at once?
Yes. Download all sheets gives a ZIP with one JSON file per sheet.
Why is a value a number in JSON but formatted in Excel?
JSON keeps the stored value, so 12.5% becomes 0.125 and a currency cell becomes a plain number. Use CSV output if you need the text exactly as displayed.
Are formulas included?
The result saved in the file is used, not the formula itself.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.