CSV to JSON Converter
Turn CSV, TSV, or semicolon-delimited data into clean JSON — with header detection, type inference, and a live table preview.
✓ Converted5 rows × 6 columns · delimiter: comma
▤ CSV input
[ { "id": 1, "name": "Ada Lovelace", "role": "admin", "city": "London, UK", "active": true, "score": 98.5 }, { "id": 2, "name": "Grace Hopper", "role": "author", "city": "New York", "active": true, "score": 97 }, { "id": 3, "name": "Alan Turing", "role": "editor", "city": "Manchester", "active": false, "score": 95.2 }, { "id": 4, "name": "Katherine Johnson", "role": "author", "city": "Hampton", "active": true, "score": "" }, { "id": 5, "name": "Margaret \"Peggy\" Hamilton", "role": "admin", "city": "Boston", "active": true, "score": 99 } ]
42 lines · 685 bytes JSON
What this tool does
Paste CSV data — exported from Excel, Google Sheets, a database, or an API — and this tool converts it to JSON as you type. It auto-detects the delimiter (comma, semicolon, tab, or pipe), handles quoted fields with embedded commas and line breaks, and can infer types so 42, true, and null become real JSON values instead of strings. Everything runs locally in your browser — your data is never uploaded.
How to use it
- Paste your CSV into the left pane (or click Load sample).
- Check the status bar — it shows the detected delimiter, row count, and column count, and flags rows with a mismatched number of fields.
- Pick the output shape: Array of objects keyed by the header row, or Array of arrays for raw rows.
- Copy or Download the JSON — or open the Table tab to sanity-check the parse.
Frequently asked questions
Is my data uploaded anywhere?
No. Parsing and conversion run entirely in your browser. Nothing is sent to a server, logged, or stored.
How are quoted fields handled?
The parser follows RFC 4180: fields wrapped in double quotes may contain the delimiter, line breaks, and escaped quotes (
""). A field like "Portland, OR" stays one value.What does "infer types" do?
Values that look like numbers, booleans, or
null are emitted as native JSON types; everything else stays a string. Turn it off to keep every value quoted — useful for zip codes and IDs with leading zeros.What if my CSV has no header row?
Uncheck first row is header. Objects are then keyed
column_1, column_2, … — or switch the output to Array of arrays to skip keys entirely.What happens with ragged rows?
Rows with fewer fields than the header are padded with
null; extra fields are kept in arrays mode and dropped in objects mode. The status bar warns you either way, naming the first affected row.