JSON, CSV, YAML, flipped.
Paste data in any of 9 formats. Pick what you want it to become. Get it instantly. Works entirely in your browser — your data never leaves your device.
Open source. Read the code on GitHub → MIT license, passing tests, architecture notes included.
Formats, explained.
Can I convert between any two formats?
Yes — all 72 directions are supported. The data flows through an in-memory JavaScript value between every pair, so you can go JSON → TOML → SQL → YAML and back without losing anything (as long as the structure is tabular or JSON-compatible).
What's tabular data?
An array of objects that all share the same keys. Like a spreadsheet. CSV, TSV, Markdown tables, HTML tables, and SQL all need this shape. JSON and YAML can handle nested data too, but when converting to tabular formats, nesting gets flattened or rejected.
How do you handle quotes and special characters?
Each format's escaping rules are respected. CSV wraps fields with commas, quotes, or newlines in double quotes. SQL escapes apostrophes by doubling them (O''Brien). YAML and XML use their standard escape mechanisms.
Is anything uploaded?
No. All parsing and serialization happens in your browser. Your data never leaves your device. We load js-yaml from our server for YAML support, but the conversion itself is all client-side.
What about very large files?
The tool handles multi-megabyte files but slows down past ~10,000 rows in the browser. For truly big data, use jq (for JSON), csvkit (for CSV), or write a script. This tool is for quick flips, not giant ETL jobs.
When should I pick JSON vs YAML vs TOML?
Short version: JSON when machines are the primary audience, YAML when deeply-nested humans are, TOML when flat humans are. For the long version with a decision matrix and five gotchas (including the YAML Norway problem), see our guide: JSON vs YAML vs TOML: when to use what.
What about XLSX?
Not yet. XLSX parsing would nearly double the page size because the format is essentially a zipped XML archive. For now, if you have an XLSX file, open it in a spreadsheet app and save as CSV first. XLSX support is on the list for a future version.