Specification

Migrating from older drafts

Introduction

As your schemas evolve over time, so does JSON Schema specification. This guide provides useful information help you smoothly upgrade your schemas across different specification versions

Learn how to use our migration guides and tooling (AlterSchema) to bring your work with you.

Alterschema is a tool designed to facilitate the automatic migration and transformation of JSON schemas as specifications evolve. It helps simplify schema maintenance, supports backward compatibility, and streamlines schema adjustment across versions. Read more about using AlterSchema.

Keywords Overview

This table provides an overview of keyword changes and removals in JSON Schema specifications from Draft 01 to the latest draft.

All Keywords	Specification	Draft introduction	Removed	Changed
`$anchor`	Core	2019-09	No	Partially replaced `$id`
`$comment`	Core	07	No
`$id`	Core	06	No	Replaced `id`
`$defs`	Core	2019-09	No	Replaced `definitions`
`$dynamicAnchor`	Core	2020-12	No	Replaced `$recursiveAnchor`
`$dynamicRef`	Core	2020-12	No	Replaced `$recursiveRef`
`$recursiveAnchor`	Core	2019-09	2020-12	Replaced by `$dynamicAnchor`
`$recursiveRef`	Core	2019-09	2020-12	Replaced by `$dynamicRef`
`$ref`	Core	03	No	Modified in 2019-09
`$schema`	Core	03	No	No
`$vocabulary`	Core	2019-09	No	No
`additionalItems`	Core	03	2020-12	Replaced by `items`
`additionalProperties`	Core	01	No	No
`allOf`	Core	04	No	No
`anyOf`	Core	04	No	No
`const`	Validation	06	No	No
`contains`	Core	06	No	No
`contentEncoding`	Validation	07	No	Replaced `media`.`binaryEncoding`
`contentMediaType`	Validation	07	No	Replaced `media`.`type`
`contentSchema`	Validation	2019-09	No	No
`definitions`	Validation	04	2019-09	Replaced by`$defs`
`default`	Validation	01	No	No
`dependencies`	Validation	03	2019-09	Replaced `requires` and replaced by `dependentSchemas` and `dependentRequired`
`dependentRequired`	Validation	2019-09	No	Partially replaced `dependencies`
`dependentSchemas`	Core	2019-09	No	Partially replaced `dependencies`
`deprecated`	Validation	2019-09	No	No
`description`	Validation	01	No	No
`disallow`	Core	01	04	Replaced by `not`
`divisibleBy`	Validation	02	Yes	Replaced by `multipleOf`
`else`	Core	07	No	No
`enum`	Validation	01	No	No
`examples`	Validation	06	No	No
`exclusiveMaximum`	Validation	03	No	Modified in 04
`exclusiveMinimum`	Validation	03	No	Modified in 04
`extends`	Core	01	04	Replaced by `allOf`
`format`	Validation	01	No	Modified in 04, 06, 07, 2019-09, and 2020-12
`id`	Core	03	06	Replaced by `$id`
`if`	Core	07	No	No
`items`	Core	01	No	Changed in 2020-12
`maxContains`	Validation	2019-09	No	No
`maxDecimals`	Validation	01	Yes	Replaced by `divisibleBy`
`maxProperties`	Validation	04	No	No
`maximumCanEqual`	Validation	01	03	Replaced by `exclusiveMaximum`
`media`	Hyper-Schema	04	07	Replaced by `contentEncoding` and `contentMediaType`
`minimumCanEqual`	Validation	01	03	Replaced by `exclusiveMinimum`
`minContains`	Validation	2019-09	No	No
`minProperties`	Validation	04	No	No
`multipleOf`	Validation	04	No	Replaced `divisibleBy`
`not`	Core	04	No	No
`oneOf`	Core	04	No	No
`optional`	Core	02	03	Replaced by `required`
`pattern`	Core	01	No	No
`patternProperties`	Core	03	No	No
`prefixItems`	Core	2020-12	No	Replaced `items`
`properties`	Core	01	No	No
`propertyNames`	Core	06	No	No
`readOnly`	Validation	01	No	No
`required`	Validation	03	No	No
`requires`	Core	01	03	Replaced by `dependencies`
`title`	Validation	01	No	No
`then`	Core	07	No	No
`type`	Validation	01	No	Modified in 04
`unevaluatedItems`	Core	2019-09	No	No
`unevaluatedProperties`	Core	2019-09	No	No
`uniqueItems`	Validation	02	No	No
`writeOnly`	Validation	07	No	No