What does this tool do?
This free CSV to JSON converter turns a CSV table into a JSON array of objects as you type, and converts JSON back to CSV with the reverse toggle. It runs entirely in your browser — nothing you paste is uploaded — so it is safe for any data.
How the conversion works
- The first row is the header. Each header cell becomes a key.
- Every following row becomes one JSON object:
{ "header1": value1, "header2": value2, ... }. - Types are detected: values that look like numbers,
true,false, ornullare converted to the matching JSON type. Everything else stays a string, and values with leading zeros (like007) are kept as strings so they are not mangled. - Quoted fields may contain commas, newlines, and escaped double quotes (
""), following the standard CSV format.
For example this CSV:
name,age,city Ann,30,Paris Cy,41,"Oslo, NO"
becomes:
[
{ "name": "Ann", "age": 30, "city": "Paris" },
{ "name": "Cy", "age": 41, "city": "Oslo, NO" }
]
How to use it
- Paste CSV on the left; the JSON appears live on the right.
- Choose 2 spaces, 4 spaces, or tabs with the JSON indent control.
- Copy the JSON or Download a
.jsonfile. - Switch the toggle to JSON → CSV to go back the other way.
Common uses
- Import a spreadsheet export into code that expects JSON.
- Turn analytics or CRM CSV exports into JSON for an API or script.
- Quickly reshape tabular data without writing a parser.
FAQ
Does it use the first row as keys?
Yes. The first CSV row is the header; each following row becomes a JSON object keyed by those headers.
Are numbers and booleans detected?
Yes. Values that look like numbers, true, false, or null become the matching JSON type; everything else stays a string. Leading-zero values stay strings.
Does it handle commas inside quoted fields?
Yes. Quoted fields may contain commas, newlines, and escaped double quotes, following the standard CSV (RFC 4180) format.
Is my data uploaded?
No. Everything runs in your browser; nothing you paste leaves your device.