Excel to JSON Converter

Array of objects turns each row into a record whose keys come from the header row — [{"name":"Ada","role":"Engineer"}, …] — which is what an API, database seeder, or JavaScript app usually wants. A 2D array preserves the sheet as a grid of raw values — [["name","role"],["Ada","Engineer"], …] — which is better when column order matters more than names or the sheet has no clean header row. You can switch between them without re-loading the file.

Numbers stay numbers, booleans stay booleans, and Excel date cells are emitted as ISO-8601 strings (2026-07-08T00:00:00.000Z) rather than Excel's internal serial numbers like 45123. That means the JSON is ready to consume directly — no post-processing to re-parse "12345" back into an integer or decode a date serial.

Yes. Enable "All sheets" and the output becomes a single JSON object keyed by sheet name — {"Customers":[…],"Orders":[…]} — so a multi-tab workbook exports in one pass instead of one sheet at a time, which is exactly the workflow paywalled converters tend to charge for.

For almost any API or app, array-of-objects wins: each record carries its field names, so downstream code reads row.email instead of row[3] and does not break when a column moves. Reach for the 2D array only when column order is the contract — feeding a charting library that expects [label, value] pairs, or preserving a sheet that has no meaningful header row. When in doubt, array-of-objects is the safer default and the one this tool selects for you.

Yes — parsing runs on your own machine, so there is no upload wait and no server-side row cap. A workbook with tens of thousands of rows converts in a moment; the main cost is the browser holding the resulting JSON string in memory to display it. If you are working with a genuinely massive export and only need certain sheets, convert one sheet at a time rather than enabling All Sheets, which keeps memory use lower.