Excel to JSON API, convert spreadsheets from your own code

Parsing XLSX inside an application means pulling in a spreadsheet library, handling shared strings, date serial numbers, merged cells and odd encodings, and keeping all of that patched. Many teams only need one thing: a spreadsheet goes in, clean JSON comes out. A conversion API does exactly that and keeps the parsing out of your codebase.

You call the endpoint with your API key, upload the workbook and get JSON shaped as an array of objects keyed by the header row. Before writing any code you can try the same settings in the widget here. The full reference lives on the API page, and the plain browser version is Excel to JSON.

How to convert Excel to JSON API in three steps

1. 1Create an API key in your account and send POST /v1/conversions with the file and target=json.
2. 2Pass options such as sheet, header row, json_shape and date_format in the same request.
3. 3Download the JSON from the result URL or receive a webhook when the conversion is done.

Designing a reliable spreadsheet to JSON integration

Spreadsheets sent by people are never as tidy as test files. Header rows start on row three under a title, column names contain trailing spaces, and the same field is spelled differently from one month to the next. Setting the header row explicitly and enabling trim in the request gives your code stable keys, so a renamed title row does not silently break the mapping.

Types matter more in JSON than in CSV. Numbers come out as JSON numbers, empty cells as null, and dates as ISO strings when you set date_format to ISO, which avoids the classic bug where 45382 arrives instead of 2024-03-31. Leading zeros in codes such as ZIP or SKU are kept as strings, because converting them to numbers would change the value.

For large workbooks, do not wait on the HTTP response. Submit the conversion, return immediately and let the webhook tell your system when the JSON is ready. Workbooks with passwords can be opened by passing the password in the request; it is used in memory only. If you need rows in a database rather than JSON, XLSX to SQL produces a ready script, and spreadsheets from Google can go through Google Sheets to JSON.