JSON ⇄ CSV Converter

How it works

• Everything runs client-side — no upload, no server round-trip.
• Auto-detect looks at the first non-whitespace character: { or [ is treated as JSON, anything else as CSV.
• JSON → CSV: a top-level object is treated as a single row; a top-level array is treated as one row per element. Columns are the union of all keys seen across every record, in first-seen order — missing values are left blank.
• Nested values: "Flatten" turns {"address":{"city":"NY"}} into a column address.city, and array items into tags[0], tags[1], etc. "Stringify" keeps nested objects/arrays as a single JSON-text cell instead.
• CSV → JSON: supports quoted fields, embedded delimiters, embedded newlines, and escaped quotes (""). "Infer types" converts true/false/null/numbers automatically; otherwise every value stays a string.
• Expand a.b → nested: if your CSV has dot-notation headers like address.city, this rebuilds the nested object structure on the way back to JSON.
• This is a general-purpose converter, not a schema validator — deeply irregular or mixed-shape data may need manual cleanup after conversion.