What does the JSON to TOON do?
TOON (Token-Oriented Object Notation) is a compact way to write JSON data for language model prompts. It uses indentation instead of braces and writes the column names of a uniform list once, which usually means fewer tokens than JSON. This tool converts both ways.
How to use the JSON to TOON
- Paste JSON. The TOON version appears on the right straight away.
- Choose the delimiter (comma, tab or pipe) and the indent size.
- Check the comparison: characters and estimated tokens for pretty JSON, compact JSON and TOON.
- Copy the TOON into your prompt. To go back, select Swap and the tool converts TOON to JSON.
When it helps
- Sending lists of records to an LLM with fewer tokens
- Comparing how much a payload shrinks
- Reading TOON that a model or another tool produced
Frequently asked questions
What is TOON format?
TOON, short for Token-Oriented Object Notation, is a compact, human-readable encoding of the JSON data model. It uses indentation for structure and declares array length and field names once for lists of uniform objects.
How much smaller is TOON than JSON?
It depends on the shape. Lists of objects that share the same keys shrink the most. Deeply nested or irregular data may save little or nothing, and the comparison panel shows the real numbers for your data.
Are the token counts exact?
No. They are estimates at about four characters per token. Real counts depend on the model's tokenizer, so use them to compare formats rather than as an exact bill.
Can I convert TOON back to JSON?
Yes. Select Swap, or paste TOON into the input after switching direction. The tool checks declared lengths and reports the line of any error.
Does TOON lose any data?
No. It represents the same data types as JSON: objects, arrays, strings, numbers, booleans and null. Numbers such as NaN and Infinity, which JSON cannot hold either, become null.