Convert JSON to Token-Oriented Object Notation (TOON), a text format that can reduce repeated field names in arrays of similar records. Paste JSON or open a file, then copy or download the TOON output. All JSON values are preserved and the conversion is checked by decoding it back. To choose fields or rows first, use the JSON Token Counter.
How to use it
- Paste valid JSON, open a file up to 2 MiB, or load the example.
- TOON appears automatically. Compare its token count with your original JSON.
- Review the output, then copy it or download converted.toon.
Private, local processing
This tool runs in your browser, in a background worker: nothing you paste or open is uploaded, and nothing is kept after you leave. This tool accepts up to 2 MiB of JSON and 64 levels of nesting. Filter larger files in the workspace first. Already loaded features keep working if your connection drops. Loading another tool or jq for the first time needs a connection. When one tool isn't enough, GigaJSON opens your data with a tree, a table, JSONPath/JMESPath/jq queries, transforms, diff and history.
Questions
What is TOON?
TOON stands for Token-Oriented Object Notation. It represents JSON data as readable text. For arrays of objects with the same fields, it can list field names once followed by rows of values. Nested objects and other JSON structures are supported too.
Does this converter remove or change values?
No fields or rows are removed. The converter checks that decoding the output restores the JSON values. It refuses duplicate object keys, numbers that cannot be represented precisely, or a conversion that fails this check. Whitespace and number spelling can change.
Does TOON always use fewer tokens?
No. Repeated records often benefit, but compact JSON can be smaller for other structures. The counts use o200k_base for the actual text; other tokenizers and full API requests can differ. A smaller token count does not guarantee better AI answers.
Can I use TOON anywhere I use JSON?
No. TOON has different syntax. Use it as readable prompt data when your workflow supports it; an API or parser expecting JSON still needs JSON. This tool does not call an AI model.
How large can the input be?
Up to 2 MiB of JSON and 64 levels of nesting. For larger documents, use the GigaJSON workspace to select a smaller result first.
Is my data uploaded?
No. The tool runs in your browser, in a background worker. Nothing you paste or open goes to a server, and nothing is kept after you leave the page.
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