Schema to JSON Schema | Schema Benchmarks

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.

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const 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);

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const 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);

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const 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:

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const jsonSchema = personSchema[
  "~standard"
].jsonSchema.input({
  target: "draft-2020-12",
});

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const jsonSchema = personSchema[
  "~standard"
].jsonSchema.input({ target: "draft-2020-12" });

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const jsonSchema = personSchema["~standard"].jsonSchema.input({
  target: "draft-2020-12",
});

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const 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.

Support Matrix Benchmarks

				Draft 2020-12		Draft 07		OpenAPI 3.0
Library	Version	Source	Standard JSON Schema	Input	Output	Input	Output	Input	Output
`arktype`	`2.2.8`	Native	Native
`effect`	`4.0.2`	Native
`joi`	`18.2.9`	Package
`sury`	`11.0.0`	Native	Native Opt in
`valibot`	`1.5.0`	Package	Package
`zod`	`4.6.5`	Native	Native
`zod/mini`	`4.6.5`	Native
`zod/v3`	`4.6.5`	Package

Target

Type

Library	Version	/wk	Type	Mean
`sury`	`11.0.0`	472.92K	Input	2 μs
`sury`	`11.0.0`	472.92K	Output	3 μs	1.05x
`valibot`	`1.5.0`	22.42M	Output	640 ns	3.74x
`valibot`	`1.5.0`	22.42M	Input	683 ns	3.5x
`zod`	`4.6.5`	341.7M	Output	9 μs	3.61x
`zod`	`4.6.5`	341.7M	Input	10 μs	4.15x
`zod/mini`	`4.6.5`	341.7M	Output	9 μs	3.6x
`zod/mini`	`4.6.5`	341.7M	Input	10 μs	4.13x
`zod/v3`	`4.6.5`	341.7M	Input	5 μs	2.02x
`zod/v3`	`4.6.5`	341.7M	Output	5 μs	2.06x
`joi`	`18.2.9`	n/a	Input	91 μs	37.87x

Standard JSON Schema

format_quoteGenerated schemas

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