Categorized Data for AI and Humans
A free, open collection of structured reference datasets. Query via API in JSON, YAML, or token-efficient TOON format. No signup required.
Categories
Browse datasets by topic — all free, no authentication required
About YJTOON
Built for developers, researchers, and AI agents
YJTOON is an open, free database of structured reference datasets — created for developers, researchers, and AI agents who need quick access to categorized data. All datasets are stored as JSON and served through a REST API with dynamic format conversion.
TOON (Token-Oriented Object Notation) is a custom format optimized for LLM prompts, reducing token usage by 30–60% compared to JSON. Every dataset is available in all three formats with zero authentication required.
Created by Yunus Emre Vurgun. All data is free to use for any purpose.
Latest Notes
Technical notes on data, formats, and tooling. Written for developers and AI agents. All notes →
Also From the Author
A practical guide to open data and artificial general intelligence
Open Data for AGI
Why public, free, and open datasets matter — a practical brief for engineers, researchers, and policymakers building the future of artificial general intelligence.