Excel to JSON
JSON arrays keyed by the first row, made for data pipelines
Drag & drop files here
or browse files
Supports .xlsx / .xls / .csv - one array per worksheet
About this tool
Feeding mock data to a frontend, writing scripts or seeding i18n copy - JSON beats hand-copying tables every time. This tool exports every worksheet of .xlsx / .xls / .csv files as JSON: the first row becomes the field names by default, turning each row into an object, or switch it off for plain arrays.
Values are written exactly as Excel displays them (dates, percentages, readable), and multi-sheet workbooks group by sheet name. Preview and tweak the result, copy it, or download a .json file. Conversion runs locally in your browser - nothing is uploaded.
Features
- Supports .xlsx / .xls / .csv - one JSON array per worksheet
- First row as field names; blank headers become columnN
- Switchable array-of-arrays output
- Display values - dates and percentages read as shown
- Editable preview, one-click copy, .json download
How to use
- Drop or select the spreadsheet file
- Toggle "first row as keys"
- Click Convert
- Copy from the preview or download the .json
Frequently asked questions
- What does the JSON structure look like?
- By default each worksheet is an array of objects keyed by the first row; turn it off for arrays of arrays. Multi-sheet workbooks group under sheet names.
- What about blank or duplicate headers?
- Blank headers become column1, column2, ... and duplicates follow last-write-wins, so tidy the header row first when in doubt.
- What types do dates and numbers get?
- Strings matching the displayed value (2026/1/5, 12.5%). For raw numeric or serialized dates, read the file with a script instead.
- Why not just use Python pandas?
- No environment, no code - the browser does it in one page, and sensitive tables stay on your device because nothing is uploaded.