JSON Schema Generator
Paste any JSON value and instantly get a JSON Schema (draft-07) describing it. Nested objects, arrays and mixed types are inferred automatically, with an option to mark all keys required. Perfect for OpenAI function calling, tool definitions and API request validation. Generation runs entirely in your browser.
🔒 Privacy: all processing happens locally in your browser. Nothing is uploaded.
Related tools
Token Counter
Count tokens with real OpenAI tokenizers (cl100k_base / o200k_base).
TokenTokenizerGPT
LLM API Cost Calculator
Estimate any LLM API cost from token counts and your own per-1M-token prices.
LLMAPICost
Chat to OpenAI Messages
Convert a plain chat transcript into OpenAI messages JSON.
ChatMessagesOpenAI
LLM API Tester
Send a test request to any LLM API and get curl, Python, Node, Go and PowerShell code.
LLMAPITest