JSON to CSV converter
MarkDone turns JSON arrays and API responses into spreadsheet-ready CSV. It flattens nested objects and arrays into clear dotted columns, escapes fields that contain commas or quotes, and can add a UTF-8 BOM so the file opens cleanly in Excel — all on your device, with no upload.
JSON is great for code but awkward in a spreadsheet. Convert an array of objects into rows and columns, with the union of all keys becoming the header, so you can sort, filter, and share in Excel or Google Sheets.
Real JSON has objects inside objects. MarkDone flattens them into dotted column names so nothing is lost, or you can disable flattening to keep nested values as JSON text in a single cell.
No. JSON to CSV conversion runs entirely in your browser. API responses and internal data stay on your device.
By default they are flattened into dotted columns such as address.city or items.0.name. You can turn flattening off to keep nested values as JSON text inside one cell.
Yes. Enable "Add UTF-8 BOM" so Excel detects the encoding, and choose CRLF line endings for maximum compatibility.
Comma, semicolon, tab, or pipe. Semicolon is useful for locales where Excel expects it.
An array of objects works best and becomes one row per object. A single object becomes one row, and an array of arrays is written directly as rows.