JSON to CSV Converter — Flatten Nested Objects
Convert JSON arrays and objects to CSV format with our free browser-based converter. Paste your JSON data and get a clean CSV output with proper headers extracted from JSON keys.
The converter handles nested objects by flattening them into dot-notation columns (e.g., address.city). Download the result as a .csv file ready for Excel or Google Sheets.
The hard part of this conversion is not the commas — it is deciding what the columns are when your objects do not all have the same keys. The converter takes the union of every key it sees, so a record missing a field gets an empty cell rather than shifting every column after it. Nested objects are flattened into dot notation (address.city), values containing commas, quotes, or newlines are quoted and escaped to RFC 4180, and the download opens cleanly in Excel, Numbers, and Google Sheets without an import wizard.
How to use JSON to CSV
- Paste your JSON array or object in the left input box.
- The converter will automatically flatten nested objects to dot notation.
- Click Convert to generate the CSV format.
- Copy the output or download it as a .csv file.
Features
- Flatten nested JSON objects automatically — Complex structures become flat CSV columns.
- Extract headers from JSON keys — Column headers are taken from the object keys, including keys that appear in only some rows.
- Download as .csv file — Open directly in any spreadsheet software.
- Handle arrays of objects and mixed types — Handles complex JSON structures.
- Configurable delimiter — Comma, tab, or semicolon output.
- 100% client-side — Data stays private.
Frequently Asked Questions
How do I convert nested JSON to CSV?
Our converter automatically flattens nested objects using dot notation. For example, {"user": {"name": "John"}} becomes a column named "user.name" with value "John."
Can I open the CSV output in Excel?
Yes. Click "Download CSV" and open the file directly in Microsoft Excel, Google Sheets, or any spreadsheet application. The format is fully compatible.
Does it handle JSON arrays?
Yes. The converter expects a JSON array of objects. Each object becomes a CSV row, and object keys become column headers.
What happens when my objects have different keys?
Every key seen anywhere in the data becomes a column, and records that lack it get an empty cell. This is the behaviour you want for API exports where optional fields appear on only some records — the alternative, using the first object's keys as the header, quietly drops data and is a common source of silent loss.
How are commas and quotes inside my values handled?
Fields containing a comma, a double quote, or a line break are wrapped in double quotes and internal quotes are doubled, following RFC 4180. That is what stops an address like "Tbilisi, Georgia" from splitting into two columns when the file is opened in a spreadsheet.