Discover other powerful utilities designed to supercharge your workflow and boost productivity.
Easily convert PDF bank statements from thousands of banks worldwide into clean Excel (XLS) or CSV format. 100% free, secure, and accurate. Trusted by accountants and businesses.
Create beautiful quote images with custom backgrounds, gradients, and social media branding. Perfect for Instagram, Twitter, Facebook, and TikTok.
AI-powered baby name generator that runs 100% offline. Find the perfect name with meanings based on gender, cultural origin, name style, and more.
Convert between JSON and TOON format to save 30-60% tokens for LLM prompts with clean, human-readable output
Click the mode button to switch between JSON → TOON or TOON → JSON conversion. The converter is bi-directional, allowing seamless conversion in both directions.
Paste your JSON or TOON data into the input editor, or click "Open File" to load from a file. The converter will validate and process your data in real-time.
When converting JSON to TOON, customize the output with these options:
When converting to TOON, check the token statistics panel to see how many tokens you're saving. This helps you optimize your LLM prompts for cost efficiency.
Use the "Copy" button to copy the converted output to your clipboard, or click "Download" to save it as a file for later use.
TOON (Token-Oriented Object Notation) is specifically designed to reduce token usage when working with Large Language Models (LLMs), while maintaining human readability and structure. Here are the key benefits:
TOON typically reduces token count by 30-60% compared to formatted JSON, especially for uniform arrays of objects. This translates to significant cost savings when working with LLMs.
TOON's explicit array lengths [N] and field headers help LLMs track structure better, achieving 73.9% accuracy vs JSON's 69.7% in benchmarks.
TOON maintains readability with YAML-like indentation and CSV-like tabular format. It's easy to read, edit, and understand at a glance.
Excels with uniform arrays of objects - define fields once, then stream data as rows. Ideal for datasets, API responses, and structured data.
{
"users": [
{ "id": 1, "name": "Alice", "role": "admin" },
{ "id": 2, "name": "Bob", "role": "user" }
]
}users[2]{id,name,role}:
1,Alice,admin
2,Bob,userTOON (Token-Oriented Object Notation) is a compact, human-readable serialization format designed specifically for passing structured data to Large Language Models with significantly reduced token usage. It's a lossless, drop-in representation of JSON data optimized for LLM contexts.
TOON typically saves 30-60% tokens compared to formatted JSON, especially for uniform arrays of objects. The actual savings depend on your data structure - tabular data with many repeated keys benefits most, while deeply nested or non-uniform data may see smaller savings.
The choice depends on your data and use case:
Yes! This converter is bi-directional. Click the mode button to switch to "TOON → JSON" conversion. TOON is designed to be a lossless format, so you can convert back and forth without losing data.
TOON excels with uniform arrays of objects, but there are cases where other formats are better:
Absolutely! All conversion happens entirely in your browser using client-side JavaScript. Your data never leaves your device, is not sent to any server, and is not stored anywhere. This tool is 100% privacy-focused.
The token counter provides an approximation based on typical GPT-style tokenization patterns. Actual token counts may vary slightly depending on the specific tokenizer used by your LLM (GPT-4, Claude, etc.). Use it as a guide for relative savings rather than exact counts.
Yes! TOON is production-ready and follows a stable specification (v2.0). However, it's designed primarily for LLM input/output, not as a replacement for JSON in APIs or storage. Use JSON programmatically and convert to TOON for LLM contexts.
Start converting your JSON to TOON format today and reduce your LLM costs by up to 60%.