About JSON to TOON Converter
How to Convert JSON to TOON
- Paste or type your JSON content in the left editor
- The tool validates your JSON and shows any syntax errors
- Click the arrow button to convert to TOON format
- View the estimated token savings percentage
- Copy or download the TOON result for use in your LLM prompts
Frequently Asked Questions
What is TOON format?
TOON (Token-Oriented Object Notation) is a compact, human-readable encoding of JSON data designed to minimize tokens for LLM input. It uses YAML-style indentation for nested objects and CSV-style tabular format for uniform arrays, declaring field names once instead of repeating them for every record.
How much can TOON reduce token usage?
For uniform arrays of objects (like user lists, log entries, or product catalogs), TOON can reduce token usage by 30-50% compared to standard JSON. The savings depend on your data structure - more uniform arrays mean greater savings.
When should I use TOON instead of JSON?
Use TOON when sending structured data to LLMs like ChatGPT or Claude, especially for uniform arrays of objects. It's ideal for data analysis prompts, batch processing, and any scenario where token costs matter. Avoid TOON for deeply nested or non-uniform structures.
Is TOON lossless?
Yes, TOON is fully lossless and deterministic. Converting JSON to TOON and back preserves all data and structure exactly. It's designed as a translation layer - use JSON programmatically and encode as TOON for LLM input.
Which LLMs support TOON?
TOON works with any LLM that accepts text input, including ChatGPT, GPT-4, Claude, Gemini, and open-source models. The format is designed to be easily parsed by both LLMs and humans.