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OTYOnlineToolYard

JSON to TOON Converter — Token-Oriented Object Notation

Convert JSON to TOON format — compact, LLM-optimised notation that cuts token costs by 30–60%.

→
TOON Output
▸ TOON format quick reference

Nested object

JSON
{"user":{"id":1,"name":"Alice"}}
TOON
user:
  id: 1
  name: Alice

Scalar array

JSON
{"tags":["admin","ops","dev"]}
TOON
tags[3]: admin,ops,dev

Uniform object array (tabular)

JSON
{"rows":[{"id":1,"name":"Alice"},{"id":2,"name":"Bob"}]}
TOON
rows[2]{id,name}:
  1,Alice
  2,Bob

String quoting

JSON
{"url":"http://example.com:8080","val":"true"}
TOON
url: "http://example.com:8080"
val: "true"

How to Use

  1. Paste your JSON into the left pane — the tool also accepts JSON5 (trailing commas, comments).
  2. The TOON output appears instantly in the right pane, following the official TOON specification.
  3. The token savings bar shows the estimated token count for both formats and the percentage reduction (based on ~4 characters per token).
  4. Click Copy to copy the TOON output and paste it directly into your LLM prompt.

Frequently Asked Questions

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