About CSV to JSON

Convert CSV data to JSON format. Part of the DevTools Surf developer suite. Browse more tools in the Converters collection.

Use Cases

• Data scientists converting CSV datasets to JSON for web-based visualization
• Backend devs importing CSV uploads as JSON for API processing
• Frontend devs transforming CSV spreadsheet exports for JavaScript apps
• Data engineers converting CSV data lake exports to JSON for NoSQL databases

Tips

• Verify that the first CSV row is correctly used as JSON keys
• Check that numeric strings are parsed as numbers, not strings
• Review the handling of empty CSV cells in the JSON output

Fun Facts

• CSV-to-JSON conversion is one of the most common data transformations, with npm's csvtojson package getting over 2 million weekly downloads.
• Papa Parse, the most popular JavaScript CSV parser, can process a 1 GB CSV file in under 30 seconds in Node.js.
• The lack of data types in CSV means converters must infer types, which can incorrectly parse zip codes like '07001' as number 7001.

FAQ

How does it handle nested data?

CSV is flat, so the output is a flat JSON array by default. Toggle 'nested keys with dots' to expand `user.name` columns into nested objects.

What about type inference?

By default all values are strings. Toggle 'infer types' to parse numbers, booleans, and null. Ambiguous strings (leading zeros, phone numbers) keep their string form.

Does it handle quoted cells with newlines?

Yes — RFC 4180 compliant. Quoted cells can span multiple lines. The parser tracks quote state correctly.

Can I rename columns?

Not in the tool — run the output through a JSON transformer if you need to remap keys. The conversion preserves source column names verbatim.