NDJSON Converter moves data between three shapes: newline-delimited JSON, a single JSON array, and CSV rows.
When NDJSON rows are flat objects it can produce a CSV with a column per key, and a CSV with a header row can become NDJSON objects. It runs in your browser.
Newline-delimited JSON, also called JSON Lines: one complete JSON value on each line. It is common for logs and data streams.
Only if every line is a flat object. The columns are the union of all the keys seen, with blanks where a row lacks one.
Simple ones are: a cell of digits becomes a number, true and false become booleans, and empty stays an empty string.