I got tired of writing JSON Schema by hand, so I built a tool that generates it from any JSON sample

Paste any JSON → get a draft-07 schema with inferred types, required fields, nested objects, and format hints (email, uuid, date-time, uri) — all in your browser, nothing sent to a server.

One thing I added that I haven't seen elsewhere: a "Smart Mode" for null fields. Most generators just output {"type": "null"} when a field is null, which rejects everything once your API sends a real value. Smart Mode outputs a union type with a refine hint instead, so your schema doesn't break immediately.

There's also a type-mapping table for Kafka Avro if you're bridging formats.

Would love feedback — what would make this more useful for your workflow?

🔗 jsondevtools.org/json-schema-generator.ht