Convert CSV to JSON and back, all in your browser. Custom delimiters, RFC 4180 quoted-field parsing, automatic type inference, header detection, and live preview. Your data never leaves your device.
CSV (Comma-Separated Values) and JSON (JavaScript Object Notation) are two of the most common data interchange formats in modern software. CSV dominates spreadsheet exports, data warehouses, and legacy systems; JSON is the lingua franca of REST APIs, NoSQL databases, and JavaScript ecosystems. This bidirectional converter bridges the two, handling the edge cases that trip up naive split-on-comma implementations.
"")"42" → 42, "true" → true, empty strings → nullfield_0, field_1, ...The parser reads CSV input character by character, tracking quote state to correctly handle delimiters and newlines embedded inside quoted fields. The first row becomes the JSON object keys (when "Has header" is checked), and each subsequent row becomes one JSON object. With type inference enabled, numeric and boolean strings are converted to their proper JSON types.
Comma, tab, semicolon, and pipe are built-in. The custom field accepts any single character, so you can parse exotic formats. Tab-separated values (TSV) work natively by selecting the tab option. The delimiter is also used in reverse for JSON → CSV output.
Yes. The parser is RFC 4180 compliant, meaning fields wrapped in double quotes can contain the delimiter, line breaks, and escaped quotes (a doubled "" character represents a literal quote inside a quoted field). On the reverse path, JSON → CSV automatically wraps any field containing special characters in quotes and escapes internal quotes.
CSV is purely textual — every cell is a string. With type inference on, the converter detects numeric values (42, 3.14, -1.5e10), booleans (true, false), and nulls (empty string or the literal text null) and emits them as proper JSON types. Disable it if you need every value to remain a quoted string.
No. Conversion runs entirely in your browser using vanilla JavaScript. Your CSV and JSON data is never sent to any server, which makes this tool safe for sensitive business data, financial records, or proprietary datasets.