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Reducing LLM Token Usage and Boosting Speed with JSON to TOON

Feb 04, 20266 min read

In the age of AI and large language models (LLMs), structured data is everywhere, and JSON has long been the standard for organizing it. But when feeding JSON directly into LLM prompts, every brace, quote, and repeated key adds extra tokens—slowing responses, increasing costs, and reducing usable context. That’s where TOON comes in.

By using a JSON to TOON converter, you can transform standard JSON into a TOON format that is compact, human-readable, and optimized for LLM prompts. This approach reduces token usage, improves model comprehension, and streamlines AI workflows.

What Is TOON?

TOON (Token-Oriented Object Notation) is a format designed for one purpose: minimizing token usage when sending structured data to large language models (LLMs). Unlike traditional JSON—which wastes tokens on braces, quotes, and punctuation—TOON removes unnecessary symbols such as quotes, curly braces, and commas.

TOON vs JSON: Why It Matters

JSON was built for machine-to-machine communication, not for tokenized language models. LLMs tokenize every character, meaning JSON's structure becomes expensive noise. TOON uses a clean, table-like structure where:

  • The first line defines the header
  • Each following line represents a row
  • Nesting is handled through indentation
  • Values are separated by pipes | or tabs
JSON Equivalent
[
  { "id": 101, "name": "Sarah" },
  { "id": 102, "name": "Omar" }
]
TOON Format
id | name
101 | Sarah
102 | Omar

Key Benefits for AI Performance

  1. Token Savings: Converting JSON to TOON can cut token usage by 30–70%, allowing you to fit more information into the same context window.
  2. Better Accuracy: By increasing the signal-to-noise ratio, LLMs can focus on the actual data rather than parsing complex structural syntax.
  3. Faster Responses: Fewer tokens mean faster inference times and lower API costs.
  4. Improved RAG: Fits more documents into retrieval-augmented generation pipelines, providing the model with more context.

The Hybrid Strategy

The most powerful modern AI architecture uses a hybrid approach:

  • Application Layer: Keep your databases and APIs in JSON for stability.
  • Conversion Layer: Right before sending data to an LLM, convert it to TOON.
  • Instruction Layer: Tell the model the data is in TOON format.

Ready to optimize your prompts?

Try our free tool to instantly transform your JSON data into token-efficient TOON format.