TOON Formatter

Re-encode TOON (Token-Oriented Object Notation) into canonical, consistently formatted TOON. Useful when hand-editing data for LLM prompts.

Free No sign-up Runs in your browser
Input TOON
Output TOON

How to use the TOON Formatter

  1. Paste your TOON into the input box, or open a file.
  2. The output updates automatically as you type.
  3. Copy the TOON or download it as a file.

About TOON

TOON (Token-Oriented Object Notation) is a compact encoding of JSON designed for LLM prompts. It uses YAML-style nesting and CSV-style rows for uniform arrays, typically cutting token counts substantially compared with JSON.

Private by design

Developer data is often sensitive: API responses, tokens, customer records, internal configs. This TOON Formatter processes everything locally in your browser tab. There is no server round-trip, no logging and no storage of your input.

Frequently asked questions

Is this TOON Formatter free?

Yes. This TOON Formatter is completely free to use with no sign-up, no limits and no ads inside the tool.

Is my data uploaded to a server?

No. The TOON Formatter runs entirely in your browser using JavaScript. Nothing you paste is sent to DevT Pro or any other server.

Can I use the TOON Formatter offline?

Yes. TOON Formatter is also built into DevT Pro, a native app for Mac, Windows, iPad and Linux with 120+ developer tools that work fully offline. It is a $5.99 one-time purchase with no subscription.

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DevT Pro

TOON Formatter, offline, plus 120+ developer tools.

Converters, formatters, encoders, validators, code generators and more in one native app. No internet, no account, no uploads.

$5.99 one-time · All 120+ tools · No subscription