How to Convert JSON to TOON: Complete Guide

As Large Language Model costs continue to rise, developers face a critical challenge: how can I reduce token consumption without sacrificing data quality? The answer lies in understanding and implementing JSON to TOON conversion—a technique that can reduce your LLM API costs by 30-60% while actually improving model accuracy.

TOON (Token-Oriented Object Notation) is a specialized data format engineered specifically for LLM consumption. Unlike JSON, which was designed for universal compatibility, TOON optimizes every character, delimiter, and syntax element for token efficiency.

This comprehensive guide walks you through the entire JSON to TOON conversion process, explains the underlying mechanics, provides practical examples, and demonstrates real-world implementations that save thousands of dollars annually on LLM API costs.

What is JSON to TOON Conversion?

JSON to TOON conversion is the process of transforming your JSON data into TOON format—a token-optimized serialization standard. The conversion isn't a simple data transformation; it's an intelligent restructuring that applies pattern detection and compression algorithms to maximize token efficiency.

Why Convert JSON to TOON?

Dramatic Token Savings

The primary motivation is cost reduction. Independent benchmarks consistently show 30-60% token reduction across diverse datasets:

Improved Model Accuracy

Counterintuitively, the more efficient TOON format often improves LLM performance. Testing across major models shows TOON achieving 86.6% accuracy compared to JSON's 83.2%—a 3.4% improvement while using nearly half the tokens.

Cost Impact at Scale

For organizations making 1 million LLM API calls monthly:

The Conversion Process: Step-by-Step

Step 1: Prepare Your JSON Data

Begin with valid, well-formed JSON. You can source JSON from multiple places:

API Responses:

{
  "users": [
    { "id": 1, "name": "Alice", "role": "admin" },
    { "id": 2, "name": "Bob", "role": "user" }
  ]
}

Database Exports:

{
  "products": [
    { "sku": "A1", "qty": 2, "price": 9.99 },
    { "sku": "B2", "qty": 1, "price": 14.5 }
  ]
}

Configuration Files:

{
  "database": {
    "host": "localhost",
    "port": 5432
  }
}

Step 2: Choose a Conversion Tool

Online Converters (Free, No Installation)

The easiest way to convert JSON to TOON is using our free online JSON to TOON converter. These tools work directly in your browser with no data sent to servers.

Programmatic Libraries (For Automation)

For automated workflows and production systems, use programmatic libraries:

import { encode, decode } from '@byjohann/toon'

const data = {
  users: [
    { id: 1, name: 'Alice', role: 'admin' },
    { id: 2, name: 'Bob', role: 'user' }
  ]
}

const toon = encode(data)
console.log(toon)

import ptoon

data = {
    "users": [
        {"id": 1, "name": "Alice", "role": "admin"},
        {"id": 2, "name": "Bob", "role": "user"}
    ]
}

toon_str = ptoon.encode(data)
print(toon_str)

use ToonPhp\Toon;

$users = [
  ['id' => 1, 'name' => 'Alice'],
  ['id' => 2, 'name' => 'Bob']
];

$toon = Toon::encode($users);
echo $toon;

Step 3: Input Your JSON

Online Method:

1. Copy your JSON data
2. Paste into the JSON to TOON converter's input field
3. The converter validates JSON syntax automatically
4. Review any errors highlighted

Programmatic Method:

const fs = require('fs')
const { encode } = require('@byjohann/toon')

const rawJson = fs.readFileSync('data.json', 'utf-8')
const jsonObject = JSON.parse(rawJson)
const toonOutput = encode(jsonObject)

Step 4: Execute the Conversion

Online:

Click "Convert to TOON" button—conversion happens instantly in your browser using our JSON to TOON converter.

Command Line:

# Using npm CLI tool
npx @toon-format/cli data.json -o data.toon

# Show token savings statistics
npx @toon-format/cli data.json --stats

Programmatic:

// Node.js
const { encode } = require('@byjohann/toon')

const json = require('./data.json')
const toon = encode(json)
console.log(toon)

Step 5: Review and Use Output

The converter displays comprehensive statistics:

Real-World Conversion Examples

Example 1: Simple User Records (Ideal for TOON)

{
  "users": [
    { "id": 1, "name": "Alice", "role": "admin" },
    { "id": 2, "name": "Bob", "role": "user" },
    { "id": 3, "name": "Charlie", "role": "user" }
  ]
}

users[3]{id,name,role}:
  1,Alice,admin
  2,Bob,user
  3,Charlie,user

What Happened During Conversion:

1. Detected tabular format (all objects have identical structure)
2. Extracted field names: id, name, role
3. Created header: users[3]{id,name,role}:
4. Output one row per line, comma-delimited
5. Removed all braces, quotes (where safe), and JSON syntax overhead

Example 2: E-Commerce Products

{
  "inventory": [
    { "sku": "A1", "qty": 2, "price": 9.99 },
    { "sku": "B2", "qty": 1, "price": 14.5 },
    { "sku": "C3", "qty": 5, "price": 3.25 }
  ]
}

inventory[3]{sku,qty,price}:
  A1,2,9.99
  B2,1,14.5
  C3,5,3.25

Example 3: Non-Uniform Data (Limited Benefit)

{
  "items": [
    { "id": 1, "name": "Widget" },
    { "id": 2, "quantity": 5 },
    "simple_string"
  ]
}

items[3]:
  - id: 1
    name: Widget
  - id: 2
    quantity: 5
  - simple_string

Example 4: Analytics Time-Series Data

{
  "metrics": [
    { "date": "2025-01-01", "views": 1523, "clicks": 48 },
    { "date": "2025-01-02", "views": 1687, "clicks": 52 },
    { "date": "2025-01-03", "views": 1834, "clicks": 61 },
    ...177 more days...
  ]
}

metrics[180]{date,views,clicks}:
  2025-01-01,1523,48
  2025-01-02,1687,52
  2025-01-03,1834,61
  ...

Why Such High Savings? Large uniform datasets multiply the benefit—keys declared once (small overhead) then hundreds of compact rows (massive savings).

Conversion Tools Comparison

Best Practices for JSON to TOON Conversion

✅ DO:

• Convert uniform arrays: Focus on data where all objects have identical structure
• Use for large datasets: TOON benefits compound with more rows (10+ items minimum)
• Test before deploying: Verify token savings match expectations with your specific data
• Keep JSON for storage: Use JSON in your database, convert to TOON only for LLM consumption
• Monitor savings: Track actual token reduction in production
• Use our free converter: Test conversions online before implementing programmatically

❌ DON'T:

• Convert deeply nested data: TOON is less efficient with 3+ levels of nesting
• Use for non-uniform arrays: Objects with varying fields won't benefit much
• Convert small datasets: Overhead isn't worth it for <10 items
• Replace JSON everywhere: TOON is for LLM optimization, not general data interchange
• Ignore validation: Always validate JSON before conversion to avoid errors

Common Issues and Solutions

Getting Started Today

Quick Start Code Example

For programmatic conversion, install the library and start converting:

npm install @byjohann/toon

import { encode } from '@byjohann/toon'

// Your JSON data
const users = {
  users: [
    { id: 1, name: 'Alice', role: 'admin' },
    { id: 2, name: 'Bob', role: 'user' }
  ]
}

// Convert to TOON
const toon = encode(users)

// Use in LLM prompt
const prompt = `Analyze this user data:\n\n${toon}\n\nHow many admins are there?`

console.log(prompt)

Conclusion

Converting JSON to TOON is a powerful optimization technique that can dramatically reduce your LLM token costs while improving model accuracy. By following this guide, you can:

• Convert JSON to TOON using online tools or programmatic libraries
• Save 30-60% on LLM token usage across your applications
• Improve model accuracy by 3-7% with more efficient data representation
• Scale cost savings to thousands of dollars annually

Whether you're working with API responses, database exports, or analytics data, the JSON to TOON conversion process is straightforward and delivers measurable results. Start with our free online JSON to TOON converter to test your data, then implement programmatic conversion for production workflows.

Ready to optimize your LLM costs? Try converting JSON to TOON now and see the difference for yourself.

Learn More About TOON

Explore these related articles to deepen your TOON knowledge:

• What is TOON Format? - Understand the fundamentals
• TOON vs JSON: Complete Comparison - See detailed benchmarks
• TOON Documentation - Full syntax reference and examples
• Contact Us - Questions? We're here to help
• Browse All Articles - More TOON tips and tutorials