How it works
- Paste CSV or upload a .csv file.
- Leave separator detection on or select the correct delimiter.
- Convert and review the first rows in the preview.
- Copy or download the formatted JSON array.
Practical example
A header name,city followed by Ada,London becomes [{"name":"Ada","city":"London"}]. Each header names one JSON property.
Formula and explanation
The first CSV record is treated as the header. Empty headings receive predictable column names, while duplicate headings are rejected because they would overwrite JSON properties.
The parser supports quoted commas, embedded line breaks and doubled quotation marks. It also reports rows whose field count differs from the header instead of discarding or shifting data.
CSV has no universal type information, so values remain strings. This avoids turning identifiers such as 00123 into a number or guessing that a date belongs to a particular timezone. Processing stays in the browser.