CSV to JSON Converter

How to Use the CSV to JSON Converter

The CSV to JSON Converter transforms comma-separated value data into structured JSON format. This is a frequently needed data transformation for web developers, data analysts, and anyone working with APIs that require JSON input from spreadsheet or database exports.

How to Convert

Paste your CSV data into the input area or upload a CSV file. The first row is automatically detected as headers (column names), which become JSON property names. Click Convert to generate the JSON output. Copy the result or download it as a .json file.

Configuration Options

Delimiter: Choose comma (default), semicolon, tab, or pipe as the field separator. European CSV files often use semicolons because commas are used as decimal separators.

Header Row: Toggle whether the first row contains column headers. Without headers, properties are named "field1", "field2", etc.

Output Format: Choose between an array of objects (most common), an array of arrays, or a keyed object using a specified column as the key.

Example Conversion

Input CSV: name,age,city followed by Alice,30,New York and Bob,25,Chicago. Output JSON: [{"name":"Alice","age":"30","city":"New York"},{"name":"Bob","age":"25","city":"Chicago"}]. The converter preserves all data and maps headers to property names.

Handling Edge Cases

The converter correctly handles quoted fields containing commas, newlines within quoted fields, escaped quotation marks, empty fields, and Unicode characters. These edge cases frequently cause issues with naive CSV parsing, but this tool follows the RFC 4180 specification for robust parsing.

Frequently Asked Questions

Q: Does the converter handle large files?

A: The converter processes files up to several megabytes efficiently in the browser. For very large datasets (100MB+), consider using command-line tools or server-side scripts. The browser-based converter works well for typical data files with thousands of rows.

Q: Can I convert JSON back to CSV?

A: Yes. The tool includes a reverse mode that converts JSON arrays of objects back to CSV format. Property names become column headers, and values populate the rows. Nested objects are flattened using dot notation (address.city becomes a column).

Q: How does the converter handle different data types?

A: By default, all values are output as strings. Enable the type detection option to automatically convert numeric strings to numbers, "true"/"false" to booleans, and empty fields to null. This produces cleaner JSON for use with typed APIs and databases.