Many libraries can convert a schema into a JSON Schema, so it can be consumed by anything that speaks JSON Schema - documentation generators, OpenAPI builders, LLM structured outputs.
We benchmark whichever API the library provides, using a small schema with a codec. Libraries that generate JSON schemas at build time (e.g. typia) are not included — there's nothing to time at runtime.
Copy to clipboardconst schema = z.object({ id: z.number(), name: z.string(), price: z.codec(z.string(), z.number(), { decode: Number, encode: String }), }); const jsonSchema = z.toJSONSchema(schema);
Because of the codec, the input and output types differ (price is a string going in, a number coming out), and so do their JSON schemas.
Standard JSON Schema
Some libraries also implement the Standard JSON Schema interface, which lets a tool generate a JSON schema without specialising for each library:
Copy to clipboardconst jsonSchema = personSchema["~standard"].jsonSchema.input({ target: "draft-2020-12" });
The Standard JSON Schema column shows how each library supports it:
- Native - the library implements it
- Native Opt in - implemented, but it has to be enabled first (e.g.
S.enableStandardJSONSchema()) - Separate package - a separate package implements it (e.g.
@valibot/to-json-schema) - None (blank) - nothing implements it, so only the library's own API is benchmarked
Generated schemas
Every generated schema is checked against the data it describes, but libraries don't agree on what a JSON schema for the same type looks like - each result links to what its library generated.