What is TOON Format? Understanding Token-Oriented Object Notation
TOON (Token-Oriented Object Notation) is a revolutionary compact data format designed specifically for Large Language Model (LLM) prompts. Unlike traditional JSON, TOON prioritizes token efficiency while maintaining human readability, making it the ideal choice for developers and AI practitioners who want to reduce API costs and maximize context window usage.
When you use our free JSON to TOON converter, you're transforming verbose JSON data into a streamlined format that LLMs like ChatGPT, Claude, GPT-4, and other AI models can easily understand. This conversion typically results in 20-60% token savings, directly translating to lower API costs and the ability to include more data in your prompts.
Why Convert JSON to TOON? Key Benefits
💰 Save Money on API Costs
LLM APIs like OpenAI and Anthropic charge per token. By reducing your token count by 20-60%, you directly cut your API expenses. For high-volume applications, this can mean thousands of dollars in savings.
📊 Fit More Data in Context
Every LLM has a context window limit. TOON's compact format lets you include more data within these limits, enabling richer prompts and better AI responses without hitting token caps.
⚡ Faster Response Times
Fewer tokens mean faster processing. Your API calls complete more quickly, improving the user experience in applications that rely on real-time AI responses.
👁️ Human & AI Readable
TOON isn't just machine-efficient—it's designed to be easily readable by both humans and AI models. The format is self-documenting with clear schema definitions.
JSON vs TOON: Side-by-Side Comparison
See the dramatic difference in token efficiency between standard JSON and TOON format:
❌ JSON (Verbose - More Tokens)
{
"users": [
{
"id": 1,
"name": "Alice",
"email": "alice@example.com",
"role": "admin"
},
{
"id": 2,
"name": "Bob",
"email": "bob@example.com",
"role": "user"
}
]
}
✓ TOON (Compact - Fewer Tokens)
users[2]{id,name,email,role}:
1,Alice,alice@example.com,admin
2,Bob,bob@example.com,user
How to Use the JSON to TOON Converter
- Paste Your JSON: Copy your JSON data from any source—API responses, configuration files, database exports, or any structured data.
- Validate (Optional): Click "Validate JSON" to ensure your data is properly formatted before conversion.
- Click Convert: Hit the "Convert to TOON" button to instantly transform your JSON into token-efficient TOON format.
- Review Token Savings: See exactly how many tokens you're saving with the before/after comparison.
- Copy and Use: Copy the TOON output directly into your ChatGPT, Claude, or any LLM prompt.
Real-World Use Cases for JSON to TOON Conversion
- ChatGPT & Claude Prompts: Include structured data in your AI prompts while staying within token limits. Perfect for data analysis, code generation, and context-heavy conversations.
- API Cost Optimization: Reduce your OpenAI, Anthropic, or other LLM API costs by sending compact TOON instead of verbose JSON in your programmatic prompts.
- RAG Applications: Improve Retrieval-Augmented Generation systems by storing and retrieving data in TOON format, maximizing the amount of context you can include.
- AI Agent Development: Build more efficient AI agents that can process more data per request, improving decision-making capabilities.
- Prompt Engineering: Create better prompts by including more examples and data points within the same token budget.
- Documentation & Examples: Share data examples in a compact, readable format that's easy to understand and copy.
Understanding TOON Format Syntax
TOON uses a schema-first approach where the data structure is defined once, followed by the actual values:
# Array with schema definition
arrayName[count]{field1,field2,field3}:
value1,value2,value3
value4,value5,value6
# Object notation
objectName{field1,field2}:
value1,value2
# Nested structures
parent{child{nested1,nested2}}:
(nestedValue1,nestedValue2)
Tool Features
Verify your JSON syntax before conversion
See exact token savings in real-time
Instantly copy TOON output to clipboard
Client-side processing - data never leaves your browser
No registration, no limits, completely free
Load example JSON to see how it works
📚 Learn More About TOON Format
Visit toonformat.dev for the official specification, detailed documentation, and additional tools for working with Token-Oriented Object Notation.