Free TOON Formatter Online
Format and beautify TOON data instantly in your browser — no signup needed.
Input TOON
Formatted TOON
What Is a TOON Formatter?
If you work with AI APIs or LLM prompts, you have probably hit token limits. TOON (Token-Oriented Object Notation) solves exactly that — it's a compact structured format that carries the same data as JSON but in far fewer tokens. It's similar in spirit to YAML — readable and structured — but designed for machine consumption. When you receive raw or minified TOON from an API or generate it programmatically, a formatter makes the structure immediately readable. The JSON RFC 8259 and TOML are related data format standards worth knowing. This tool adds indentation and line breaks so you can debug, review, or share TOON without squinting at a single compressed line.
A TOON formatter adds indentation and line breaks to raw or minified TOON so you can read the structure clearly. The page parses your TOON and prints it back out with consistent nesting, all inside the tab, so prompts full of production records or customer data stay on your machine.
TOON Formatting Examples
Format TOON for readability. Telecom-themed example:
Example: Subscriber records
Formatted output:
Click the Sample button above to load more examples into the editor.
How to Use This Tool
Paste or Upload
Copy your TOON and paste it into the left editor. You can also click Upload to load a .toon or .txt file. The Sample button loads example data. Invalid TOON will show an error—use the TOON Validator to diagnose.
Check the Output
The right panel updates automatically. Valid TOON gets formatted with proper indentation. If there's a syntax error, you'll see an error message instead.
Copy or Download
Grab the tidied TOON with Copy, or keep it as a file with Download. If you need JSON out of it, use TOON to JSON. For the reverse, use JSON to TOON.
When TOON Formatting Helps
TOON is used when sending structured data to LLMs, AI APIs, or token-limited systems. Compared to JSON, TOON uses fewer tokens. If you receive minified TOON from an API or generate it programmatically, formatting it here makes the structure readable for debugging or review. The RFC 8259 JSON spec and YAML are related formats. Developers working with AI prompts and structured outputs often need to inspect TOON before or after processing.
Config and schema data in TOON format benefits from formatting before sharing with teammates. Running it through the TOON Validator first can catch syntax issues. For converting to JSON, YAML, or other formats, use the TOON converter tools.
Frequently Asked Questions
Is my data private?
Yes. Re-indenting TOON is handled by the page's own script, so the records you paste are not uploaded anywhere. The Network tab in DevTools will back that up if you watch it while formatting.
What is the difference between TOON and JSON?
TOON is more compact and uses fewer tokens — great for LLM prompts and AI API calls. JSON is universal and supported everywhere. Use TOON when token budget matters; use JSON for general APIs and config files.
Can I convert TOON to JSON?
Yes. Use the TOON to JSON tool linked in Related Tools. The conversion preserves the full structure and values.
What if my TOON is invalid?
The formatter will show a parse error. Use the TOON Validator to get detailed error messages with line and position so you can pinpoint and fix the issue.
Does formatting change the data?
No. Only whitespace and indentation change. The structure and values stay exactly the same. Formatted TOON is semantically identical to the original.
Related Tools
Learn more: TOON, JSON spec, MDN JSON, RFC 8259, YAML, GitHub, TOML.