json2toon.co
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Convert JSON
to TOON & TONL

Free online JSON to TOON and TONL converter optimized for Large Language Models. Transform your data to save up to 45% tokens, reduce API costs, and maximize context window efficiency with Token-Oriented Object Notation (TOON) and Token-Optimized Notation Language (TONL).

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InputJSON
OutputTOON

100% Client-Side Security

Your data never leaves your browser. All transformations from JSON, YAML, or XML happen locally, ensuring maximum privacy for sensitive information.

Lightning Fast Conversion

Experience instant JSON to TOON and TONL conversion with zero server latency. Supports large files, batch processing, and multiple format transformations.

How to Convert JSON to TOON & TONL

Follow these simple steps to optimize your data for LLMs in seconds using TOON or TONL formats.

1

Paste Data

Copy your JSON, CSV, YAML, or XML data and paste it into the input editor.

2

Convert

The tool automatically detects your format and converts it to optimized TOON or TONL format instantly.

3

Copy & Use

Copy the result and paste it into ChatGPT, Claude, or your LLM prompt to save tokens.

Why use TOON & TONL for LLMs?

Reduce Token Costs

TOON and TONL remove redundant syntax like quotes and brackets, saving 20-45% of tokens. Learn more in our cost optimization guide.

Human Readable

Unlike minified JSON, TOON remains easy for humans to read and edit while being machine-optimized.

Get Started with TypeScript/JavaScript
comparison.jsonStandard JSON
[
  {
    "id": 1,
    "name": "Alice",
    "role": "Admin"
  },
  {
    "id": 2,
    "name": "Bob",
    "role": "User"
  }
]
vs
optimized.toonTOON/TONL Format
[2]{id,name,role}:
  1,Alice,Admin
  2,Bob,User
Example showing ~40% token reduction using TOON/TONL serialization.

Learn More About TOON & TONL

Discover in-depth comparisons, optimization strategies, and real-world use cases for TOON and TONL formats in our blog.

Read Our Blog