How to Convert JSON to TOON for AI Applications

If you're sending JSON data to ChatGPT, Claude, or other AI models, you're wasting tokens—and money. Converting JSON to TOON can reduce your token usage by 30-60%.

This guide shows you exactly how to convert your data and start saving immediately.

Why Convert JSON to TOON?#

Every character in your AI prompts costs tokens. JSON's syntax—all those braces, brackets, and quotes—adds up fast:

30-60% token reduction with same semantic content
Lower API costs at $0.01-0.03 per 1K tokens
More context space for actual data within limits
100% lossless conversion back to JSON

At Scale	JSON Cost	TOON Cost	Monthly Savings
100K tokens/day	$90/month	$36/month	$54
1M tokens/day	$900/month	$360/month	$540
10M tokens/day	$9,000/month	$3,600/month	$5,400

Step-by-Step: Using the Converter#

Converting JSON to TOON takes seconds:

Go to JSON to TOON Converter
Paste your JSON in the left panel
Click Convert — see instant TOON output
Check token count — displayed for both formats
Copy or download the TOON output

Toggle Direction: Use the switch to convert TOON back to JSON when needed.

Conversion Example#

Here's a real-world example of API data conversion:

before-json.jsonjson

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

TOON Output#

The same data in TOON format:

after-toon.toontext

users
  [3]
  id, name, role
  1, Alice, admin
  2, Bob, user
  3, Carol, user
total: 3

Token reduction: ~55%

Using TOON in AI Prompts#

When including TOON data in your prompts, consider adding a brief format note for best results:

You are analyzing user data. The following is in TOON format (a compact JSON alternative with tabular arrays):

users
  [3]
  id, name, role
  1, Alice, admin
  2, Bob, user
  3, Carol, user

Analyze the role distribution and provide insights.

Programmatic Conversion#

For integrating into your codebase, you can use our conversion logic:

// Using the TextGauge library (conceptual)
import { jsonToToon, toonToJson } from '@textgauge/toon';

// Convert JSON to TOON
const jsonData = '{"name": "John", "age": 30}';
const toonData = jsonToToon(jsonData);
// Result: "name: John\nage: 30"

// Convert back to JSON
const backToJson = toonToJson(toonData);
// Result: '{"name":"John","age":30}'

When NOT to Use TOON#

TOON is designed for AI/LLM use cases. Avoid it for:

REST APIs — Clients expect standard JSON
Configuration files — JSON/YAML are standard
Browser storage — localStorage uses JSON
Database fields — JSON is BSON-compatible

Use TOON for:

AI prompts with structured data
RAG system context injection
Fine-tuning dataset preparation
Any LLM API call with data payloads

Frequently Asked Questions

Is TOON conversion reversible?▼

Yes, 100% lossless. Convert JSON → TOON → JSON and get identical data back. All types, nesting, and structure are preserved.

Do I need to tell the AI about TOON format?▼

For simple data, no. For complex or large datasets (100+ items), adding a brief "This data is in TOON format" note improves parsing accuracy.

Can I use TOON with any LLM?▼

Yes, TOON works with GPT-4, Claude, Gemini, Llama, and other models. The format resembles YAML, which is well-represented in training data.

How much can I realistically save?▼

Real-world savings of 30-60% are typical. Arrays of objects see the highest savings (up to 64%) due to header deduplication.

Start Saving on AI Tokens

Convert your JSON to TOON and see the token savings instantly. Free, private, no sign-up required.

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Fundamentals

What is TOON Format

Learn about TOON (Token-Optimized Object Notation) - the data format designed for AI applications that reduces token usage by 30-60% compared to JSON.