Free Online CSV ↔ JSON Converter
Convert CSV spreadsheet data into JSON arrays of objects, or transform JSON back into CSV format. The first row of your CSV is treated as column headers, and every subsequent row becomes a JSON object with those keys. All processing stays in your browser, so sensitive data like client lists, sales records, and internal reports never leave your computer.
How to Use
- Select the conversion direction: CSV → JSON or JSON → CSV
- Paste your source data into the input area
- Click Convert and the result appears instantly
- Copy the output or use it directly in your code or spreadsheet
Features
- Bi-directional conversion between CSV and JSON
- Handles quoted fields and commas within values
- Real-time validation with clear error messages
- 100% local processing - nothing leaves your device
CSV Format Notes
This converter treats the first line of CSV as column headers. Each header becomes a JSON key, and each subsequent line becomes an object with those keys. Values containing commas, quotes, or line breaks should be wrapped in double quotes. Leading and trailing whitespace is trimmed from each value.
JSON Format Notes
JSON input must be an array of objects. Each object should have the same keys, which will become CSV column headers. Values are converted to strings for CSV output. Empty or missing fields are preserved as empty values in the CSV.
Privacy
All data conversion happens locally in your browser. Nothing is sent to any server.
Limitations
This tool handles flat CSV data with simple delimiters. It does not support tab-delimited TSV, nested JSON, or Excel-exported CSVs with BOM markers. For complex data transformation, review the output before using it in production.
Last reviewed: July 2026.