Convert JSON to TOON format instantly and reduce LLM token usage by up to 60%. Free online converter optimized for ChatGPT, Claude, and Gemini. Save API costs today.
TOON to JSON Converter
JSON to TOON Converter
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TOON and JSON examples
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans to read and write and easy for machines to parse and generate. It is based on a subset of JavaScript but is language-independent, with parsers available for virtually every programming language.
Key Features of JSON:
Simple key-value pair syntax
Supports nested objects and arrays
Data types: strings, numbers, booleans, null
Widely supported across all platforms
Human-readable and machine-parseable
{"name":"John Doe","age":30,"skills":["Python","JavaScript","DevOps"],"address":{"street":"123 Main St","city":"Springfield","zip_code":12345}}
What is TOON?
TOON (Token-Oriented Object Notation) is a minimal data serialization format specifically designed to reduce token consumption in Large Language Model applications. Created to optimize AI API costs, TOON eliminates redundant syntax like braces, brackets, and excessive quotes while maintaining data structure through indentation. It maps unambiguously to JSON and is used for AI applications, chatbots, RAG systems, and any LLM workflows where token efficiency matters.
Key Features of TOON:
Minimal syntax for maximum token efficiency
Supports comments using #
Indentation-based structure (similar to Python/YAML)
Arrays defined with simple indentation
up to 60% token reduction compared to JSON
Direct compatibility with JSON data structures
name: John Doe
age: 30
skills[3]: Python,JavaScript,DevOps
address:
street: 123 Main St
city: Springfield
zip_code: 12345
Frequently Asked Questions
TOON (Token-Oriented Object Notation) is a data format specifically designed to reduce token consumption in Large Language Model applications. Converting JSON to TOON typically saves up to 60% tokens by eliminating redundant syntax like braces, brackets, and excessive quotes while maintaining data structure through indentation. Since LLM API costs are based on token consumption, TOON conversion can significantly reduce expenses for AI applications, chatbots, RAG systems, and data-heavy LLM workflows.
Simply paste or type your JSON data into the input field. The converter automatically transforms it to TOON format in real-time as you type-no button clicks needed for conversion. You'll instantly see the token count comparison showing your savings. Click the 'Copy to clipboard' button to copy the TOON output for use in your LLM prompts or API calls. If your JSON contains syntax errors, an error message will appear with details about the issue.
Independent benchmarks show JSON to TOON conversion achieves up to 60% token reduction depending on your data structure. Arrays of uniform objects see the highest savings-often 50-60% reduction. Since LLM providers charge based on token consumption, reducing tokens by up to 60% translates directly to proportional cost savings. Applications making thousands of LLM API calls daily can reduce monthly costs by 40-50% through TOON conversion.
Yes, all major LLMs including GPT-4, GPT-5, Claude, Gemini, and other models understand TOON format natively. TOON uses simple, readable syntax similar to YAML with CSV-style tables, which LLMs already handle well. Benchmarks show LLMs achieve 86.6% accuracy with TOON compared to 83.2% with JSON, meaning converting JSON to TOON not only saves tokens but can actually improve model comprehension and response accuracy.
Absolutely. All JSON to TOON conversion happens entirely in your browser using JavaScript-no data is sent to external servers or stored anywhere. This client-side architecture ensures complete privacy and security for sensitive data including API keys, personal information, or proprietary business data. Your JSON never leaves your device, making the converter safe for confidential projects.
TOON excels with arrays of uniform objects (like user lists, product catalogs, analytics data, database exports) where it achieves 50-60% token reduction. Nested structures and configuration files also benefit with 30-40% savings. Pure tabular data converts efficiently to TOON's CSV-style format. The converter handles all valid JSON, though deeply nested non-uniform structures may see smaller gains. The tool shows real-time token counts so you can see exact savings for your specific data.
Learn how TOON format reduces LLM token usage by up to 60%. Discover when to use TOON vs JSON, how to convert between them, and save on ChatGPT, Claude, and Gemini API costs.