JSON to TOON Converter

Optimize your LLM prompts with Token-Oriented Object Notation

Why Use TOON Format?

✓Save 30-60% on LLM tokens compared to formatted JSON for uniform arrays
✓LLM-friendly validation with explicit length markers and field headers
✓Human-readable format that combines YAML-like structure with CSV-like compactness
✓Perfect for passing structured data to Claude, GPT, and other LLMs

Benchmarks show 73.9% accuracy using 39.6% fewer tokens compared to JSON's 69.7% accuracy. Learn more at toonformat.dev

Conversion Mode

Indentation

Delimiter

Fold Keys

JSON Input

TOON Output