Excel to JSON Converter
Turn .xlsx, CSV and TSV sheets into API-ready JSON in your browser
Excel .xlsx, CSV or TSV, up to 15 MB
Open an .xlsx, .csv or .tsv file to start.
What it converts
Excel to JSON turns .xlsx workbooks, CSV and TSV files into JSON you can paste into code, fixtures or API requests. Pick a sheet, choose how the header row maps to keys, and get an array of objects, an array of arrays, or every sheet keyed by its name. Numbers, booleans and text keep their types.
Dates, formulas and errors
A number is treated as a date only when its cell has a date or time format, so IDs and amounts never turn into dates. Dates can be ISO 8601 text, the formatted text shown in Excel, or the raw serial in the workbook date system, including 1904 workbooks. Formula cells use the result saved in the file and are not recalculated, and error cells such as #N/A are kept as text and counted.
Headers and structure
Blank and duplicate headers are listed in the review panel. Duplicates can get a _2 suffix or stop the conversion, header text can be trimmed or converted to camelCase or snake_case, and dot keys such as address.city can become nested objects. A cell range such as B2:F40 limits the conversion to one block, and empty rows can be skipped. Merged cells keep their value in the top-left cell only, so values are never duplicated.
Privacy and limits
The file is read with the File API and processed in a background worker in your browser; nothing is uploaded. Files up to 15 MB and 250,000 filled cells are supported, the preview shows the first 50 rows and 30 columns, and very large JSON is shortened in the editor while Copy and Download always include everything. Legacy .xls, .xlsb, macro-enabled and password-protected workbooks are not supported; save them as .xlsx first.
