CSV ↔ JSON Converter
Convert between CSV and JSON formats for data interchange and processing. CSV to JSON creates arrays of objects using the first row as keys. JSON to CSV generates properly formatted CSV with automatic headers. Full RFC 4180 compliance including quoted fields, embedded commas, newlines within cells, and custom delimiters.
What does this tool do?
The CSV-JSON converter provides bidirectional translation optimized for data processing workflows. CSV to JSON parses CSV data into JavaScript arrays of objects, with the header row becoming object keys. It handles quoted fields, escaped quotes (doubled quotes), embedded commas, and newlines within cells. JSON to CSV converts arrays of objects to CSV format, automatically generating headers from object keys and properly quoting fields that contain special characters. Custom delimiter support (comma, tab, semicolon, pipe) accommodates various regional and application-specific formats.
How it works
For CSV to JSON: the parser reads the first line as headers, then subsequent lines as data rows. RFC 4180 parsing handles quoted fields ("...") that can contain commas and newlines, escaped quotes as """, and trims whitespace based on options. Each row becomes an object with header keys. For JSON to CSV: the tool extracts all unique keys from the array of objects to form the header. Each object is serialized to a row, with values converted to strings and quoted if they contain the delimiter, quotes, or newlines. Papa Parse library provides robust CSV parsing with edge case handling.
Features
- CSV → JSON array of objects (first row as keys)
- JSON → CSV with auto-generated header
- RFC 4180 quoted fields with embedded commas/quotes/newlines
- Custom delimiter: comma, tab, semicolon, pipe
- Optional trim of whitespace around fields
- Header toggle (treat first row as data vs headers)
- Live conversion with error reporting
How to use
- 1
Select direction
Choose CSV → JSON to parse tabular data to objects, or JSON → CSV to flatten objects to tabular format.
- 2
Paste input
Enter CSV data or JSON array. Output updates live as you type for small inputs, or use convert button for larger data.
- 3
Adjust options
Set delimiter if not comma. Toggle 'Has header' for CSV (off means first row is data, keys become col1, col2...).
- 4
Review and copy
Verify the conversion looks correct. Copy the result for use in spreadsheets, databases, APIs, or code.
Common use cases
Data import/export
Convert between CSV for spreadsheets/databases and JSON for APIs and JavaScript applications.
API data preparation
Convert CSV datasets to JSON format for POST requests to REST APIs that expect JSON payloads.
Spreadsheet integration
Convert JSON API responses to CSV for analysis in Excel, Google Sheets, or data visualization tools.
Database operations
Prepare CSV data for database imports, or convert query results to JSON for application consumption.
Tips & best practices
- CSV has no standard for nested data — nested objects/arrays in JSON become [object Object] or JSON string representations in CSV
- Always check delimiter if parsing fails — European CSV often uses semicolon (;) instead of comma
- Quoted fields in CSV can contain the delimiter: "Smith, John",25 is a single name field with a comma inside
- For TSV (tab-separated values), select Tab as the delimiter — common in bioinformatics and Unix command output