How do I convert CSV to JSON in Dart?

Call decodeToMaps to get a list of maps keyed by header name, then pass that to jsonEncode. Numeric columns are already numbers, so the JSON is not all strings.

CSV to JSON and maps

Get CSV into the shape the rest of your program already speaks.

Install#

dart pub add csv_plus

import 'package:csv_plus/csv_plus.dart';

Rows as maps#

final maps = CsvCodec().decodeToMaps('name,age\nAlice,30\nBob,25');
// [{name: Alice, age: 30}, {name: Bob, age: 25}]

Straight to JSON#

import 'dart:convert';
import 'package:csv_plus/csv_plus.dart';

final maps = CsvCodec().decodeToMaps(csv);
final json = jsonEncode(maps);

Because inference already produced real int and double values, the JSON contains numbers rather than quoted strings.

A two-column CSV as a map#

CsvCodec().decodeMap('host,localhost\nport,8080');
// {host: localhost, port: 8080}

CsvCodec().encodeMap({'host': 'localhost', 'port': 8080});

Fusing with dart:convert#

final adapter = CsvCodec().asCodec(); // Codec<List<List<dynamic>>, String>

adapter.decode('a,b\n1,2');
final piped = adapter.fuse(utf8);