JSON to Yup Schema

Create Yup validators from JSON shapes

Yup schemas validate form values and API data at runtime, but nested declarations are tedious to write from a large example. This converter walks a JSON object and emits yup.object, yup.array, and scalar validators for each value. Whole numbers receive integer validation, non-null sample fields are marked required, and nested records remain structured instead of being reduced to generic mixed values.

With the default input, userSchema requires user_id as an integer number, name as a string, and active as a boolean. Nested profile data becomes an embedded required object, while a list uses yup.array().of with an inferred child validator. The output can seed a Formik form schema or protect an API boundary after you adapt its rules.

Required fields and semantic validation

A concrete payload reveals syntax but not every business rule. The generator cannot know minimum lengths, accepted enum values, email formats, or whether a field may be absent elsewhere. Null becomes a nullable mixed validator and empty arrays use mixed members. The sample stays in your browser. Review required markers and add domain-specific tests before treating the schema as authoritative.