Convert Excel (XLSX) to JSON Online Free

Need spreadsheet data in your code? AllConvert converts XLSX to JSON instantly, right in your browser — each row becomes an object, ready for any API or app. No upload, no account.

Why convert XLSX to JSON?

JSON is what code speaks: web apps, REST APIs, NoSQL databases and config files all consume JSON. When the source data lives in an Excel sheet — a product list, translations, test fixtures, a pricing table — converting it to JSON turns each spreadsheet row into an object your program can use directly, with no Excel parsing library required in your project.

What shape does the output have?

The first row of the sheet is treated as the header: its cells become the keys. Every following row becomes one JSON object, and the whole sheet becomes an array of objects — the shape virtually all code expects. Only the first sheet of the workbook is converted, so reorder sheets first if needed.

Round trips and related formats

Need to load JSON back into Excel later? AllConvert converts JSON to XLSX too. For a lighter intermediate format, XLSX to CSV followed by CSV to JSON gives you the same result with an inspectable middle step.

How to convert

1. Drag your XLSX file into the converter at the top of this page, or click the box to select it.
2. The sheet is parsed and converted to JSON right away on your device — your data stays on your machine.
3. Click the download button that appears to save the JSON file.

Conversion happens locally in your browser tab; nothing is uploaded, and the result is ready in seconds on desktop or mobile.

How cell types map to JSON

Excel doesn't tag a cell as "string" or "number" the way JSON does — it stores raw content plus a display format, so the parser infers the type. Numbers come across as JSON numbers, text as strings, and checkboxes as booleans. Dates are the case worth watching: internally Excel stores a date as a serial number counting days from December 30, 1899, so depending on how the cell is formatted you might get a plain number back instead of a readable date — check a few rows after converting if your sheet has date columns. As with CSV, formulas are exported as their last calculated value, and only the first sheet becomes JSON.

Frequently asked questions

What JSON structure do I get from an Excel file?
An array of objects: the first row supplies the keys, and each row after that becomes one object — the shape most code and APIs expect.

Can I convert a specific sheet of the workbook?
AllConvert converts the first sheet. Move the one you need to the first position in Excel before converting.

Is my spreadsheet uploaded to a server?
No. Parsing and conversion happen entirely in your browser, so your data never leaves your device — safe even for business-sensitive spreadsheets.