JSON → TSV writes one row per object (union of keys) or per array; tabs, newlines and backslashes inside values are escaped as \t \n \\ so every row stays on one line; nested values are JSON text; formula-like cells are neutralized. TSV → JSON reverses it with a header row → objects or arrays, and optional type inference. Limits: 20,000 rows, 500 columns, 1,000,000 cells. Everything runs locally.