The Complete JSON to TOON Conversion Guide

Learn how to convert JSON to TOON format with practical examples, best practices, and step-by-step instructions to reduce your LLM token usage.

TutorialTOONJSONConversion

Converting your JSON data to TOON format is the fastest way to start saving on LLM API costs. This comprehensive guide will walk you through everything you need to know about JSON to TOON conversion, from basic syntax to advanced patterns.

Why Convert JSON to TOON?

Before we dive into the how, let's quickly recap the why:

  • Reduce token consumption by 30-60%
  • Lower API costs across all LLM providers
  • Fit more data in context windows
  • Faster processing with fewer tokens

Understanding the Fundamental Differences

JSON Structure

{
  "key": "value",
  "nested": {
    "property": "data"
  },
  "array": [1, 2, 3]
}

TOON Structure

key: value
nested:
  property: data
array: [1, 2, 3]

Token savings: TOON eliminates redundant curly braces, quotation marks around keys, and excessive punctuation.

Basic Conversion Rules

1. Simple Key-Value Pairs

JSON:

{
  "name": "Alice",
  "age": 28,
  "city": "New York"
}

TOON:

name: Alice
age: 28
city: New York

Rule: Remove curly braces and quotes around keys. Keep one key-value pair per line.

2. Nested Objects

JSON:

{
  "user": {
    "name": "Bob",
    "email": "bob@example.com",
    "address": {
      "street": "123 Main St",
      "city": "Boston"
    }
  }
}

TOON:

user:
  name: Bob
  email: bob@example.com
  address:
    street: 123 Main St
    city: Boston

Rule: Use indentation (2 spaces) to represent nesting instead of curly braces.

3. Arrays

JSON:

{
  "colors": ["red", "green", "blue"],
  "numbers": [1, 2, 3, 4, 5]
}

TOON:

colors: [red, green, blue]
numbers: [1, 2, 3, 4, 5]

Rule: Keep arrays in bracket notation. Quotes around string values in arrays can be omitted if there are no spaces.

4. Arrays of Objects

JSON:

{
  "users": [
    {
      "id": 1,
      "name": "John"
    },
    {
      "id": 2,
      "name": "Jane"
    }
  ]
}

TOON:

users:
  - id: 1
    name: John
  - id: 2
    name: Jane

Rule: Use dash (-) for array items, followed by indented properties.

Advanced Conversion Patterns

Complex Nested Structures

JSON:

{
  "company": {
    "name": "TechCorp",
    "departments": [
      {
        "name": "Engineering",
        "employees": [
          {
            "name": "Alice",
            "role": "Senior Developer"
          }
        ]
      }
    ]
  }
}

TOON:

company:
  name: TechCorp
  departments:
    - name: Engineering
      employees:
        - name: Alice
          role: Senior Developer

Handling Special Characters

JSON:

{
  "message": "Hello, \"World\"!",
  "description": "Line 1\nLine 2"
}

TOON:

message: Hello, "World"!
description: |
  Line 1
  Line 2

Rule: Use pipe (|) for multi-line strings. Escape sequences are handled naturally.

Boolean and Null Values

JSON:

{
  "isActive": true,
  "isVerified": false,
  "middleName": null
}

TOON:

isActive: true
isVerified: false
middleName: null

Rule: Boolean and null values remain the same.

Numbers and Scientific Notation

JSON:

{
  "integer": 42,
  "float": 3.14159,
  "scientific": 1.5e10
}

TOON:

integer: 42
float: 3.14159
scientific: 1.5e10

Rule: Numeric values are preserved as-is.

Step-by-Step Conversion Process

Step 1: Analyze Your JSON Structure

Identify:

  • Depth of nesting
  • Number of arrays
  • Special characters or multi-line strings
  • Data types present

Step 2: Start with the Root Level

Remove the opening curly brace and convert top-level keys.

Step 3: Handle Nesting

Replace curly braces with proper indentation (2 spaces per level).

Step 4: Convert Arrays

Keep simple arrays in brackets. Use dash notation for arrays of objects.

Step 5: Validate the Result

Ensure:

  • Consistent indentation
  • Proper syntax for each data type
  • No missing or extra characters

Real-World Conversion Example

Let's convert a realistic API response:

JSON (Original):

{
  "status": "success",
  "data": {
    "user": {
      "id": 12345,
      "username": "johndoe",
      "email": "john@example.com",
      "profile": {
        "firstName": "John",
        "lastName": "Doe",
        "age": 30
      },
      "preferences": {
        "theme": "dark",
        "notifications": true
      }
    },
    "posts": [
      {
        "id": 1,
        "title": "My First Post",
        "likes": 42
      },
      {
        "id": 2,
        "title": "Another Post",
        "likes": 73
      }
    ]
  }
}

TOON (Converted):

status: success
data:
  user:
    id: 12345
    username: johndoe
    email: john@example.com
    profile:
      firstName: John
      lastName: Doe
      age: 30
    preferences:
      theme: dark
      notifications: true
  posts:
    - id: 1
      title: My First Post
      likes: 42
    - id: 2
      title: Another Post
      likes: 73

Token Reduction: Approximately 45% fewer tokens!

Common Conversion Mistakes to Avoid

1. Inconsistent Indentation

❌ Wrong:

user:
 name: John
   age: 30

✅ Correct:

user:
  name: John
  age: 30

2. Missing Colons

❌ Wrong:

name John

✅ Correct:

name: John

3. Incorrect Array Syntax

❌ Wrong:

items:
  [1, 2, 3]

✅ Correct:

items: [1, 2, 3]

4. Not Handling Multi-line Strings

❌ Wrong:

description: This is a very long description that spans multiple lines

✅ Correct:

description: |
  This is a very long description
  that spans multiple lines

Automated Conversion Tools

While manual conversion is educational, automated tools save time:

Benefits of Using a Converter Tool:

  • Instant conversion of large JSON files
  • Error-free syntax
  • Token count comparison before and after
  • Batch processing for multiple files
  • Validation to ensure proper TOON format

When to Use Manual vs Automated:

  • Manual: Learning TOON, small files, custom formatting needs
  • Automated: Production environments, large datasets, time-sensitive projects

Testing Your Converted TOON

After conversion, verify:

  1. Data integrity: All values preserved correctly
  2. Structure: Nesting levels match original JSON
  3. Token count: Measure actual savings
  4. LLM compatibility: Test with your target LLM API

Best Practices for Conversion

1. Keep Consistent Formatting

Use the same indentation throughout (2 spaces recommended).

2. Comment Your TOON

Add comments where needed:

# User configuration
user:
  name: John  # Primary user
  role: admin

3. Validate Before Production

Always validate converted TOON before using in production environments.

4. Version Control

Keep both JSON and TOON versions during transition period.

5. Document Your Schema

Maintain documentation of your TOON data structures for team reference.

Migration Strategy

Phase 1: Test

Convert sample JSON files and test with your LLM applications.

Phase 2: Measure

Track token usage and cost savings over a test period.

Phase 3: Gradual Rollout

Migrate one API endpoint at a time to minimize risk.

Phase 4: Full Production

Once validated, convert all JSON to TOON for maximum savings.

Conclusion

Converting JSON to TOON is straightforward once you understand the basic rules:

  • Remove unnecessary syntax overhead
  • Use indentation for nesting
  • Keep arrays concise
  • Maintain data type integrity

Whether you convert manually or use automated tools, the token savings make TOON adoption a smart choice for any LLM-powered application.

Ready to start converting? Try our free JSON to TOON converter and see your savings instantly!


Next Steps: Check out our guide on calculating your exact API savings with TOON format.