Nested JSON to CSV
Flatten an array of nested JSON objects into a clean CSV with dot-notation column headers.
This tool runs 100% in your browser. Your data is never uploaded, stored, or logged.
CSV output
About this tool
Spreadsheets don't understand nesting — but your API data is full of it. This converter flattens each object in a JSON array and produces a proper RFC-4180 CSV: dot-notation headers, quoted cells where needed, and a consistent column set across all rows even when objects differ.
Pick comma, semicolon or tab delimiters to match your locale and spreadsheet app.
How to use it
- Paste a JSON array of objects (a single object also works).
- Choose the delimiter and path separator.
- Click Run, then copy or download the CSV.
- Open it in Excel, Google Sheets or LibreOffice.
Useful ways to apply it
- Exporting API responses to Excel for non-technical teammates.
- Turning MongoDB-style documents into flat rows for analysis.
- Building quick reports from webhook payload logs.
- Feeding nested data to tools that only accept CSV.
Frequently asked questions
How are missing keys handled?
The header row is the union of all keys found. Rows missing a key get an empty cell, so columns always line up.
What happens to arrays inside objects?
Array elements become numbered columns: tags.0, tags.1 and so on.
Will commas inside values break the CSV?
No — cells containing the delimiter, quotes or newlines are quoted and inner quotes doubled per RFC 4180.
Privacy
This tool runs 100% in your browser. Your data is never uploaded, stored, or logged.