Data Format Converter
Convert between JSON, YAML, TOML, and CSV instantly in your browser. No uploads, no server — your data never leaves your machine.
🔄 4 formats
Convert between JSON, YAML, TOML, and CSV — the four formats you'll actually encounter in config files, APIs, and data pipelines.
⚡ Instant
Click Convert and your output appears immediately. No waiting, no progress bars, no round-trips to a server.
🔒 Private
Everything runs in your browser. Your configs, secrets, and data structures never leave your machine.
⇄ Swap
One click swaps the input and output formats so you can round-trip data without copy-pasting between fields.
📋 Copy & export
Copy the converted output to clipboard instantly, or export it as a file with the correct extension.
💾 Saved configs
Pro users can save named format configurations and restore them instantly — keep your common conversions one click away.
About the supported formats
JSON
JSON (JavaScript Object Notation) is the lingua franca of web APIs. It supports strings, numbers, booleans, null, arrays, and objects. Most REST APIs return JSON. Config files for tools like ESLint, Prettier, and package.json use JSON.
YAML
YAML (YAML Ain't Markup Language) is human-readable and widely used for configuration files. Docker Compose, GitHub Actions, Kubernetes manifests, and Ansible playbooks all use YAML. It supports comments, which JSON does not.
TOML
TOML (Tom's Obvious Minimal Language) is designed to be unambiguous and easy to read. It's used by Rust's Cargo.toml, Python's pyproject.toml, and Hugo config files. TOML is explicit about types in a way that YAML is not.
CSV
CSV (Comma-Separated Values) works for flat, tabular data. When converting from JSON or YAML to CSV, the top-level array of objects becomes rows. Converting CSV to JSON produces an array of objects where column headers become keys.