JSON to TOON Converter
Convert JSON to Token-Oriented Object Notation (TOON) for up to 60% fewer LLM tokens
TOON output will appear here...Why Use TOON for LLMs?
Save Money
Reduce API costs by a significant amount by using fewer tokens per request.
Faster Responses
Fewer tokens = faster processing time from GPT, Claude, and other LLMs.
LLM Optimized
TOON is designed for machine readability while staying human-friendly.
Private & Secure
Conversion happens in your browser. Nothing is sent to any server.
Real-time
See TOON output instantly as you type or paste JSON.
Developer Friendly
Copy with one click. Perfect for prompt engineering workflows.
What is TOON Format?
❌ JSON (Verbose)
{
"users": [
{ "id": 1, "name": "Alice" },
{ "id": 2, "name": "Bob" }
]
}~45 tokens
✓ TOON (Compact)
users[2]{id,name}:
1,Alice
2,Bob~18 tokens (60% savings!)
How TOON Works:
- 1.No curly braces or brackets - Uses indentation instead
- 2.Tabular arrays - Keys declared once, values as CSV rows
- 3.No repeated keys - Eliminates redundancy in arrays
- 4.Minimal quotes - Only when necessary for special characters
Perfect For
Prompt Engineering
Include structured data in prompts without burning through tokens.
API Response Parsing
Ask LLMs to return data in TOON format for cheaper structured outputs.
Fine-tuning Datasets
Use TOON in training data to reduce dataset token counts.
Agent Workflows
Pass context between agents more efficiently with TOON encoding.
Frequently Asked Questions
What is TOON?
TOON (Token-Oriented Object Notation) is a data format designed to minimize token usage when sending structured data to LLMs like GPT-4, Claude, or Gemini.
How much can I save?
For flat, tabular data (arrays of objects), you can save a significant amount on tokens. Deeply nested objects may see smaller savings or even slight increases.
Can LLMs understand TOON?
Yes! Modern LLMs easily parse TOON format. You can also include a brief format explanation in your system prompt for best results.
Is my data safe?
Absolutely. All conversion happens in your browser using JavaScript. No data is ever sent to any server.
When should I NOT use TOON?
Avoid TOON for deeply nested hierarchies. It works best for flat data like user lists, product catalogs, API responses, and tabular datasets.
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