JSON, or JavaScript Object Notation, was popularized by Douglas Crockford in early 2000. Since then, there’s been no looking back. JSON has become the standardized data exchange format between client and server technologies. JSON was built for humans...

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TOON (Token-Oriented Object Notation) is a new data serialization format designed to reduce token usage by 30-50% when exchanging structured data with large language models. Unlike JSON's verbose syntax with braces and quotes, TOON uses a compact tabular style that's more token-efficient for AI interactions. The format is available through NPM packages for JavaScript/TypeScript and Python libraries, making it easy to convert between JSON and TOON. While not a universal JSON replacement, TOON excels in AI-specific use cases where token costs and efficiency matter, such as LLM prompts, agent frameworks, and serverless AI APIs.

What is TOON? How Token-Oriented Object Notation Could Change How AI Sees Data

How to Use TOON With JavaScript / TypeScript

Hold On, JSON Might Still Be Better (In Many Cases)