ToonConverter — universal data format conversion
ToonConverter
21+ formats · 15 SDKs · 2,829 tests · MIT license

ToonConverter

Universal Data Format Conversion

Bidirectional conversion between TOON and 21+ data formats — JSON, XML, YAML, CSV, TOML, EDI, GeoJSON, KML, GPX, NPY, FITS, and more. 15 SDKs with 2,829 tests, zero external dependencies, and a ~40% token reduction for tabular data.

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21+ formats, one converter

Every format converts bidirectionally through TOON as the canonical pivot.

Core

JSON XML CSV EDI

Text / Config

TSV YAML TOML JSONC JSON5

Web Services

SOAP

Geospatial

GeoJSON KML GPX SHP

Logging

LOG Syslog

Scientific

NPY FITS MAT v5 DTA v118 RData

Why TOON?

A compact, human-readable encoding of the JSON data model that minimizes tokens.

JSON (106 chars) 
{"users":[{"id":1,"name":"Alice"},{"id":2,"name":"Bob"}]}
TOON (62 chars, -42%) 
users[2]{id,name}:
  1,Alice
  2,Bob

Why ToonConverter

Six pillars that make ToonConverter the universal choice.

🔄

21+ bidirectional formats

Convert between TOON, JSON, XML, CSV, YAML, TOML, EDI, GeoJSON, KML, GPX, NPY, FITS, MAT, DTA, RData, SHP, and more — all through TOON as the canonical pivot.

⚡

Direct serialization

Skip the JSON intermediate. Serialize native objects directly to TOON — 40-50% faster in C# and Java, zero-cost in Rust via serde.

🚫

Zero dependencies

In-house parsers for YAML, KML/GPX XML, NPY, FITS, MAT v5, DTA v118, RData, SHP. No external libraries required for core functionality.

🌐

15 SDKs, one API

Same symmetric API across Rust, Python, TypeScript, Go, Java, C#, PHP, Perl, R, C, C++, Swift, Fortran, Delphi, VB.NET.

🧪

2,829 tests, all green

Round-trip, edge-case, invalid-input, and official fixture tests across all 15 ports. SonarQube 83.7% coverage.

📜

MIT license

Fully open source. Use in any project — personal, commercial, or academic. No restrictions.

TOON vs JSON, side by side

A compact view of what changes when you adopt TOON.

Aspect JSON TOON
Tabular data size 106 chars 62 chars (-42%)
LLM token count Baseline ~40% fewer tokens
Human readability Verbose but clear Compact, table-like
Native format support Universal 21+ bidirectional converters
Direct serialization JSON.stringify() Direct (no intermediate)
Dependencies None (native) None (in-house parsers)
SDK coverage Native everywhere 15 languages
Standard ECMA-404 / RFC 8259 TOON v3.0 specification

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