JSON to TOON Converter
Represents calm, serenity, and the elegance of sophisticated simplicity.
Convert JSON to TOON format – the AI-native data format that reduces token usage by 30-60%.
Privacy Promise
Your content never leaves your browser. All processing happens locally on your device using JavaScript. We do not store, record, or transmit your input data to any server.
30-60% Token Reduction
Same data, fewer tokens, lower AI costs
Key Features
AI-Optimized Format
TOON is designed specifically for LLMs like ChatGPT and Claude. It reduces token count while maintaining perfect data fidelity.
Tabular Arrays
Arrays of objects are converted to a compact tabular format with headers declared once, similar to CSV but with explicit structure.
Bidirectional Conversion
Convert JSON to TOON and TOON back to JSON losslessly. Your data structure is preserved exactly.
100% Client-Side
All conversion happens in your browser. Your data never leaves your device, ensuring complete privacy and security.
Why TOON is Better Than JSON for AI
Token Economy
LLMs charge per token. JSON wastes tokens on repetitive syntax:
{"name": "John"} = 7 tokensname: John = 3 tokensBetter LLM Parsing
TOON's explicit structure helps AI understand data better:
- Explicit array length declarations
- Clear field headers
- Reduced ambiguity in nested structures
| Aspect | JSON | TOON |
|---|---|---|
| Token Count | 100% (baseline) | 40-70% |
| API Costs | Higher | 30-60% savings |
| Human Readability | Good | Excellent (YAML-like) |
| LLM Parse Accuracy | Variable | Improved |
| Use Case | Web APIs, Config | AI/LLM Applications |
Model-Specific Optimization (2026 Edition)
TOON is engineered to align with the attention mechanisms of modern transformer models. By stripping boilerplate syntax, you allow the model to focus its internal compute on your actual data values.
For GPT-4o & o1-Series
OpenAI models charge significantly for long contexts. TOON's tabular headers eliminate the repeat keys found in JSON arrays, effectively doubling the amount of data you can provide in a single prompt without hitting context caps.
For Claude 3.5 Sonnet
Anthropic models excel at reasoning over clean, structural data. TOON provides a "YAML-Lite" semantic structure that matches Claude's internal training on documentation, leading to higher accuracy in data extraction and summarization tasks.
Pro Tip: When using TOON with large datasets (100+ rows), include a short instruction: "The following data is in TOON format (CSV-style with headers)." This ensures the model immediately switches to its most efficient parsing mode.
