JSON to CSV Converter

A JSON to CSV converter that flattens a JSON array of objects into spreadsheet-ready CSV, building the header row from the union of all keys, filling missing values with blanks, and quoting fields containing commas or quotes.

This tool turns a JSON array into CSV: paste an array of objects and it produces a CSV with a header row assembled from the objects' keys, one line per record, ready to save and open in any spreadsheet application. APIs speak JSON, but analysis happens in spreadsheets, so when you need to eyeball an API response, share data with a colleague who lives in Excel, or import records into accounting software, converting a JSON array to CSV is the bridge.

The conversion handles the details that trip up hand-rolled scripts. Keys are collected across all objects, not just the first — so records with missing or extra fields still line up in the right columns, with blanks where a value is absent. Values containing commas, quotes or line breaks are wrapped and escaped per the CSV standard, so a note field with an embedded comma won't shift every subsequent column. The output downloads as a .csv file that Excel, Google Sheets and LibreOffice open directly.

One honest limitation: CSV is a flat, two-dimensional format, and deeply nested JSON doesn't flatten unambiguously. This converter expects an array of reasonably flat objects — the shape most list APIs return. If your objects contain nested objects or arrays, those values are serialised as JSON strings in their cell rather than exploded into extra columns, keeping the conversion lossless. Everything runs in your browser; your data is never uploaded.