Frequently Asked Questions
Yes. Enable 'Flatten nested' to convert nested objects to dot-notation columns: {name:{first:'John'}} becomes 'name.first'. Arrays inside objects are joined with semicolons.
After converting to CSV, open the .csv file in Excel or Google Sheets. It will import correctly. For Excel, use 'Data → From Text/CSV'. For Google Sheets, use File → Import.
This tool handles JSON up to a few MB comfortably in the browser. For very large files (100MB+), use command-line tools: jq (Linux/Mac) with jq -r '.[] | [.col1,.col2] | @csv' or Python's pandas library.
This converter handles inconsistent keys gracefully — each unique key becomes a column, and rows with missing keys get empty values for those columns. The header row shows all columns found.
About this calculator
Convert JSON to CSV with options for the delimiter, the quote character, a header row and flattening of nested objects. Load Sample shows how it works.
The nested-JSON option turns objects such as address.city into their own columns.
How to use it
- Paste your JSON or press Load Sample.
- Set Delimiter, Quote, Include header and Flatten.
- Press Convert to CSV.
Mapping
CSV is rows of values separated by a delimiter (usually a comma). A value containing the delimiter, a quote or a line break is wrapped in double quotes, and quotes inside are doubled ("") per RFC 4180. In JSON-to-CSV, the first row is a header made from the keys of the objects; nested objects can be flattened to dotted keys such as address.city. In CSV-to-JSON, the first row supplies the keys and every other row becomes one object.
Worked example
{"name":"Asha","address":{"city":"Pune"}}
| Flattened header | name,address.city |
| Row | Asha,Pune |
Tips and common mistakes
- Check the delimiter. Many European exports use semicolons.
- Make sure the first row is the header.
- Values with commas must be quoted.
- Nested arrays do not fit neatly in CSV; flatten or stringify them.
- Open the CSV in a spreadsheet to confirm columns line up.
Frequently asked questions
How do I convert JSON to CSV?
Paste a JSON array of objects and press Convert.
How are nested objects handled?
They can be flattened with dotted column names.
What delimiter should I use?
Comma is standard, semicolon is common in Europe.
What if keys differ between objects?
The header is the union of all keys.
How do I convert CSV to JSON?
Paste the CSV with a header row and press Convert.
Is my data uploaded?
No.