JSON ⇄ Excel Converter

What the spreadsheet looks like

Each object becomes one row and each key becomes a column header. Given two records where only the second has an email and the first has a nested address:

[
  { "name": "Asha", "plan": "pro", "address": { "city": "Pune" } },
  { "name": "Ravi", "plan": "free", "email": "ravi@example.com" }
]

the workbook gets four columns (name, plan, address, email). Asha's email cell and Ravi's address cell are blank, and Asha's address cell holds {"city":"Pune"} as text. A single JSON object (not wrapped in an array) is treated as a one-row sheet.

Limits that come from Excel itself

An .xlsx worksheet holds at most 1,048,576 rows (so 1,048,575 records plus the header row), 16,384 columns, and 32,767 characters in a single cell. The converter counts rows before it starts building the workbook and tells you straight away if the data won't fit, instead of failing halfway through. It also stops at roughly 8 million cells (rows × columns), because beyond that, building the file inside a browser tab gets impractically slow. For data that big, the JSON ⇄ CSV Converter has no row or cell limit, which matters when the next step is a database import or a script rather than a spreadsheet.

Before converting a workbook to JSON

Three spreadsheet habits cause surprises in the JSON. Merged cells keep their value only in the top-left cell, so a region name merged across five rows appears on the first record and is an empty string on the next four. Unmerge and fill down first. Extra header rows (a title above the real headers) become the keys, so delete them. Multiple sheets: only the first is read, so move the sheet you need to the front. The JSON conversion guide covers how the same data behaves in CSV, XML and YAML.

Frequently Asked Questions