Every token in an LLM prompt has a cost, and JSON is a verbose way to send structured data — property names repeat on every object in an array, and braces/brackets add up fast. TOON exists specifically to fix that.
What Is JSON to TOON?
JSON to TOON is one of the tools in WebdevToolbox’s AI & Prompt Tools category. Paste JSON and get its TOON equivalent — a line-oriented, indentation-based format that declares an array’s length and field list once instead of repeating keys on every item.
How to Use It
- Open the tool at /tools/json-to-toon.
- Paste any JSON object or array.
- Copy the generated TOON output — it updates live as you type.
- Check the token estimate below the output to see roughly how much more compact the TOON version is.
Key Features
- Tabular form for uniform arrays — arrays of objects that all share the same keys collapse into a single header line plus one comma-separated row per item.
- Minimal quoting — strings are only quoted when needed (they contain a delimiter, look like a number, or have leading/trailing whitespace).
- Rough token-savings estimate — a quick character-based approximation of how many fewer tokens the TOON version uses versus the original JSON.
- 100% private — conversion runs entirely in your browser.
When to Use JSON to TOON
- Sending structured data to an LLM prompt where every token counts toward your context window or API cost.
- Comparing formats to see how much more compact TOON is versus your existing JSON payloads.
- Preparing tabular data (lists of similarly-shaped records) for token-efficient LLM consumption.
Try It Now
Open JSON to TOON directly from anywhere on the site using ⌘K and typing the tool name.
Part of the AI & Prompt Tools collection on WebdevToolbox — free, browser-based developer tools with no login required.