Generate Production-Ready Structured Outputs
Describe the data you need from an LLM. Get an optimized System Prompt, strict JSON Schema, and ready-to-use validation code instantly.
Try an example below — instant, no account, no API key needed.
Tip: press Ctrl+Enter to generate.
Stored only in your browser (localStorage). Never sent anywhere except to OpenRouter when you click Generate. Your key pays for your own calls.
Works with OpenAI, Claude & Gemini APIs
Get API Key →
Pick an example on the left to see an instant result — no key needed.
Optimized System Prompt
// Your generated system prompt will appear here...
// Your validation code will appear here...
// The raw JSON Schema will appear here...
Instant examples are pre-built and free to copy. Custom generations are made automatically by StrictJSON's tamed models — no account, no API key needed, free up to 10 generations a day.