JSON · YAML · TOML — Tutorial

Overview

This tool lets you format and convert between JSON, YAML, and TOML — fully in your browser. You can also validate the data against a JSON Schema (subset of draft‑07), making it handy for quick config checks and transformations.

Common uses

• Prettify or minify JSON before committing
• Convert YAML/TOML configs into JSON for programmatic use
• Check a payload against a JSON Schema during development
• Translate examples across ecosystems (e.g., Python/TOML ↔ Node/JSON)

How to use

1. Choose formats — Pick the input and output formats (JSON, YAML, TOML).
2. Paste content — Paste your data into the Input box, or use Paste button.
3. Convert — Click Format / Convert to pretty‑print and convert to the target format.
4. Swap — Use Swap formats to quickly reverse conversion direction.
5. Copy/Download — Copy the output or download it as a file.
6. History — Last 5 conversions are saved locally; click View to inspect full input/output.

Open the tool: JSON · YAML · TOML — Formatter & Converter

JSON Schema validation

Paste a JSON Schema into the Schema box and click Validate. The tool converts YAML/TOML inputs to JSON internally and validates them against a small subset of draft‑07:

• type, properties, required, items
• enum, minimum/maximum, minLength/maxLength

It’s great for quick checks. For production‑grade validation (formats, refs, oneOf/allOf, etc.), use a full validator like AJV in your app.

Privacy & limits

• All conversions and validation run locally; nothing is uploaded.
• Large inputs can slow the browser; prefer download for big outputs.
• YAML/TOML support may require adding a small client‑side library. In this site, JSON works out of the box; YAML/TOML are planned.

Troubleshooting

• Parse errors: Ensure the input matches the selected format (JSON/YAML/TOML).
• Schema errors: The subset validator flags missing required fields or type mismatches; complex keywords are not supported.
• Whitespace differences: Pretty‑printing uses 2‑space indentation; exact spacing may differ from your linter.