JSON Schema Generator
Generate a JSON Schema (Draft 2020-12, 2019-09, or Draft-07) from any sample JSON. Auto-detects types, infers string formats (date, date-time, email, URI), marks populated fields as required, merges schemas across array items.
What powers the JSON Schema Generator
JSON Schema Draft 2020-12, 2019-09, or Draft-07
Type inference (string, integer, number, boolean, null, object, array)
String format detection (date, date-time, email, URI)
Schema merging across array items
Required fields auto-marked
Why the JSON Schema Generator is different
Browser-native
The JSON Schema Generator runs entirely in your browser. Input is processed locally — never uploaded, never logged, never cached anywhere outside your device.
No artificial limits
No daily quotas, no character ceilings, no "upgrade for more" walls. Every feature is the complete feature — the same on the first use as the thousandth.
Production-grade quality
Built to the same engineering bar as paid SaaS tools — accurate algorithms, audited logic, responsive design and accessibility-tested interactions.
Common use contexts
- Building OpenAPI specs from sample responses
- Database schema generation from sample data
- API request / response validation
- Documenting expected JSON shape
Private and secure
Zero upload
All processing happens in your browser. Input is never transmitted, logged or cached.
Works offline
Once the page loads, the tool runs without an internet connection. No network calls happen during use.
No tracking
No accounts, no cookies for tool state. Only aggregate analytics count visits at the page level.