About this tool
Paste CSV to get JSON — an array of objects when the first row is a header, or an array of arrays when it is not. The parser follows RFC 4180, so quoted fields, escaped quotes and newlines inside a quoted value all survive, and the delimiter (comma, tab, semicolon or pipe) is detected automatically.
The reverse direction takes an array of objects, uses the union of their keys as the header row, flattens nested objects to dotted keys, and quotes any field containing a delimiter, quote or newline. Optional type inference converts numeric and boolean-looking strings, with rules stated up front so values like leading-zero IDs are not mangled.