About JSONtoTOON

JSONtoTOON is a free, browser-based utility that converts JSON data to TOON (Token-Oriented Object Notation) format. Our single goal: help AI developers spend fewer tokens — and therefore less money — on every LLM API call, without changing the information they send.

Why we built this

JSON is the default interchange format for APIs, but it is verbose by design. Quoted keys, repeated structures in arrays, and deeply nested brackets all consume tokens that carry no additional meaning to a language model. When you are sending hundreds of API calls a day, that verbosity adds up fast.

TOON was created to address this. By representing uniform arrays in a tabular format and eliminating redundant syntax, TOON encodes the same data in 30–60% fewer tokens — without changing the underlying information. JSONtoTOON is the free, open tool that makes this conversion instant.

Our principles

  • Privacy by design. Every conversion runs entirely in your browser. No data is ever sent to a server, stored, or logged. This is not a policy choice — it is an architectural one.
  • Free, always. The converter is and will remain free to use with no rate limits, no paywalls, and no sign-up required.
  • Accuracy first. TOON conversion is lossless. JSON → TOON → JSON produces byte-for-byte identical output. We test this on every change.
  • Honest metrics. The token counts displayed come from the GPT o200k_base tokenizer, the same tokenizer used by OpenAI's GPT-4o. Actual savings in your production system will vary by model and prompt structure.

The tool

The converter is built with React 19 and Vite, runs on Apache hosting, and is designed to work on any device — desktop, tablet, or phone. It loads once and works offline after that.

The TOON encoder and decoder are custom implementations following the TOON specification, with full support for: tabular uniform arrays, nested objects, mixed-type arrays, unicode strings, and special-character escaping.

Contact

Questions, bug reports, or feedback are welcome at getinfotoyou@gmail.com. You can also use the contact form.

Last updated: June 2026