CSV to JSON

CSV (comma-separated values) is the plain-text table that every spreadsheet, database and analytics tool can export. JSON (JavaScript Object Notation) is the format most web APIs, apps and scripts read. This converter reads your CSV and writes it as a JSON array, with all the work done inside your browser.

With the header option on, the first row supplies the keys and every row after it becomes one object, so a row of Ada, 36, London becomes {"name": "Ada", "age": 36, "city": "London"}. Turn the header off and each row becomes a plain array. Empty or repeated header names are renamed (column_3, name_2) so no key is overwritten. The parser follows RFC 4180: quoted fields can contain commas, line breaks and doubled quotes, Windows and Unix line endings both work, blank lines are skipped and a byte order mark is removed.

Numbers and true/false become real JSON values only when the text would round-trip exactly, so 42 becomes a number while 007, 1.50, +1 and IDs too long to store exactly as numbers stay strings. Rows with too few fields are padded with empty strings, and the converter lists the rows that didn't match the header.