Why TOON Might Be Your Next JSON Replacement (And How to Get Started)

Source: Dev.to

The Problem with JSON (That You Probably Didn’t Know Existed)

JSON is everywhere—web development, API communication, data storage. But JSON is verbose: every quote, comma, and brace adds up. In AI/LLM applications this verbosity translates directly to higher costs and limited context windows when you pay per token.

What Makes TOON Different?

Massive Token Reduction

TOON can achieve 30‑60 % fewer tokens than JSON.

JSON

{
  "site": {
    "id": "site_123",
    "name": "My Awesome Site",
    "pages": [
      {
        "id": "page_1",
        "title": "Home",
        "components": [
          {
            "type": "hero",
            "props": {
              "title": "Welcome",
              "subtitle": "Get started today"
            }
          }
        ]
      }
    ]
  }
}

TOON

site
  id: site_123
  name: My Awesome Site
  pages
    -
      id: page_1
      title: Home
      components
        -
          type: hero
          props
            title: Welcome
            subtitle: Get started today

No quotes around keys, no commas, no braces—just an indentation‑based structure that uses roughly 40 % fewer tokens.

Faster Parsing

Because the format is simpler, TOON can be parsed up to 4.8× faster than JSON, which is valuable for real‑time, high‑throughput, or performance‑critical scenarios.

Better Readability

The indentation‑based syntax makes the data immediately clear and easier to edit manually, eliminating common JSON pitfalls like missing commas or mismatched braces.

Real‑World Impact

Testing TOON across several projects shows substantial token savings:

• The Imaginatorium (narrative/event storage): 45 % reduction
• VIBE CHAT (chat log storage): 38 % reduction
• CML Quest (game content format): 42 % reduction
• Mini‑Cursy (telemetry logging): 50 % reduction

When processing thousands of records, these percentages translate to significant cost savings and more data per context window.

Getting Started: A Working Parser & Converter

Live Demo

Try the real‑time conversion demo:

Installation

npm install toon-parser

Quick Start

const ToonConverter = require('toon-parser');

// Convert JSON to TOON
const json = {
  user: {
    name: "John Doe",
    email: "john@example.com",
    settings: {
      theme: "dark",
      notifications: true
    }
  }
};

const toon = ToonConverter.jsonToToon(json);
console.log(toon);
// Output:
// user
//   name: John Doe
//   email: john@example.com
//   settings
//     theme: dark
//     notifications: true

// Convert TOON back to JSON
const backToJson = ToonConverter.toonToJson(toon);
// Returns the original JSON object

Key Features

• ✅ Bidirectional conversion (JSON ↔ TOON)
• ✅ Round‑trip safe (perfect back‑conversion)
• ✅ Validation (syntax checking)
• ✅ Zero dependencies (lightweight)
• ✅ Browser & Node.js support

When Should You Use TOON?

Perfect For

• AI/LLM Applications – token efficiency = cost savings
• Human‑Readable Configs – easy manual editing
• Large Datasets – smaller file sizes
• Real‑Time Processing – faster parsing
• Telemetry Logs – efficient event storage
• Content Formats – narrative/story data

Stick with JSON If

• Maximum compatibility is critical
• You need extensive tooling/ecosystem support
• Browser native APIs are required
• Your team isn’t ready to adopt a new format

The Future of Data Formats

TOON isn’t meant to replace JSON everywhere, but for specific use cases—especially AI/LLM workloads, human‑editable configs, and high‑performance systems—it offers compelling advantages. The format is still evolving, and with a working parser already available, you can start experimenting today.

Resources

• Live Demo:
• GitHub Repository:
• Original TOON Article: