JSON ↔ CSV Converter
Paste a JSON array or a CSV and get the other format instantly. Handles nested objects by flattening dot-notation keys. Direction is auto-detected, or you can switch manually. Nothing uploaded.
Learn more: JSON and CSV conversion
How nested JSON flattening works
JSON objects often contain nested structures - for example, a user record with an address sub-object. CSV cannot represent nesting, so this tool flattens nested objects using dot notation. An object like {address: {city: 'London', zip: 'EC1A'}} becomes two separate CSV columns: address.city and address.zip. You control the depth of flattening: depth 1 only flattens the immediate level, while unlimited flattens all nested levels. This allows complex JSON to be exported for spreadsheet analysis.
Handling delimiters and regional variations
CSV files use different delimiters in different regions. North America and the UK primarily use commas, while many European countries (Germany, France, Spain, Netherlands) use semicolons because the comma is their decimal separator. If you export a CSV as comma-delimited but it opens as a single column in Excel, try switching to semicolon. This tool supports comma, semicolon, and tab delimiters for both import and export.
FAQ
How does nested JSON flattening work when converting to CSV?
Nested objects are flattened using dot notation. For example, {address: {city: 'London', zip: 'EC1A'}} becomes two columns: address.city and address.zip. You can control the flattening depth - depth 1 only flattens the top level, while unlimited flattens all nesting levels.
Can I convert CSV back to JSON with this tool?
Yes. The tool auto-detects direction: if your input starts with [ or { it converts JSON to CSV; otherwise it converts CSV to JSON. You can also manually set the direction. CSV to JSON produces an array of objects where the header row becomes the property names.
What delimiter should I use for CSV files in Europe?
Many European countries (Germany, France, Spain, Netherlands) use semicolons (;) as the CSV delimiter because commas are used as decimal separators. If your CSV opens as a single column in Excel, switch the delimiter to semicolon. This tool supports comma, semicolon, and tab delimiters.