When to use it
When your team's config files come in different formats. When you need to pull YAML into JSON, or turn a CSV into an array of objects for a script. Parse errors point to the exact line and column.
How it works
Pick the From and To formats at the top. Paste on the left and the
right updates live. ↔ Swap feeds the current output back as input.
Detect scans your input and guesses the format.
Per-format notes
- JSON ↔ YAML — Round-trips cleanly. Arrays and nested objects both work without coercion.
- JSON → TOML — TOML requires the root to be a table (object). If your data is a top-level array, wrap it under a key first.
- JSON ↔ CSV — CSV is tabular, so it only accepts arrays of flat objects. Nested structures raise an error.
Common pitfalls
- YAML indentation — Tabs aren't allowed. Two spaces is the norm.
- Top-level array in TOML — The root must be a table.
Wrap it:
{ "items": [...] }. - CSV numeric coercion — Strings like
"123"are parsed as numbers. Quote them explicitly if you need strings.
Sensitive payloads, both directions
JSON ↔ YAML ↔ TOML ↔ CSV parsers (yaml · @iarna/toml · papaparse) ship in the client bundle. Conversion happens in the browser without a server round-trip.