CSV ↔ JSON converter
Convert between CSV and JSON in either direction, with delimiter detection.
How it works
CSV looks trivial and is not. Splitting on commas breaks the moment a field contains one, and real-world exports contain quoted fields, embedded newlines and inconsistent line endings.
Type coercion is opt-in for a reason
Converting "007" to the number 7 destroys data — the same goes for phone numbers,
postcodes and product codes with leading zeros. This tool only converts a value when the
number round-trips to exactly the same string, so 007 and 1.50 stay
as text while 42 becomes a number.
Semicolons and locale
In locales that use a comma as the decimal separator, Excel exports CSV with semicolons instead. That is why a file that opens cleanly for a colleague can arrive as one long column for you — pick the right delimiter above rather than assuming the file is broken.
JSON → CSV flattens
The column set is the union of all keys across all rows, so heterogeneous objects produce empty cells rather than misaligned columns. Nested objects and arrays are stringified — CSV has no way to represent structure.