JSON to TOON Converter

Convert JSON to Token-Oriented Object Notation to save tokens for LLM prompts

Features

Schema-Based Compression

Extracts repeated keys into a schema for maximum efficiency

Token Counter

Shows exact token counts and savings percentage

Smart for Arrays

Perfect for JSON arrays with consistent object structures

Privacy First

All conversion happens locally in your browser

Frequently Asked Questions

TOON is a compact JSON format designed to reduce token usage when working with Large Language Models (LLMs). It extracts repeated keys from JSON arrays into a schema, significantly reducing the overall text size and token count.
When working with LLMs like GPT, Claude, or others, you pay based on token usage. TOON can reduce your JSON data size by 20-50% or more, directly lowering your API costs and allowing you to fit more data within context limits.
TOON works best with JSON arrays of objects. Instead of repeating keys in every object, TOON extracts the keys once into a 'schema' field, and the data becomes arrays of values. This eliminates redundant key repetition.
Use TOON when: 1) You're sending large JSON arrays to LLMs 2) Your JSON has many objects with the same keys 3) You want to reduce API costs 4) You need to fit more data within token limits
Yes! TOON is just a structured format. You can easily convert it back by mapping the schema keys to the data arrays. Most programming languages can handle this conversion in a few lines of code.
Our tool uses an approximate calculation where 1 token β‰ˆ 4 characters. This is a simplified estimate; actual token counts may vary slightly depending on the specific LLM tokenizer, but it provides a good approximation.