Summarising the other answers, here are the JSON schema generators proposed so far:

Online:

  • https://www.liquid-technologies.com/online-json-to-schema-converter (1 input)
  • http://www.jsonschema.net (1 input)
  • https://easy-json-schema.github.io (1 input)
  • https://json.ophir.dev/ (1 input, nice UI)

Python:

  • https://github.com/gonvaled/jskemator (1 input but allows iteration)
  • https://github.com/perenecabuto/json_schema_generator (1 input)
  • https://github.com/rnd0101/json_schema_inferencer (1 input I think)
  • https://pypi.python.org/pypi/genson/ (multiple inputs)
  • https://pypi.python.org/pypi/skinfer (multiple inputs)

NodeJS:

  • https://github.com/Nijikokun/generate-schema (multiple inputs (pass object array))
  • https://github.com/easy-json-schema/easy-json-schema (1 input)
  • https://github.com/aspecto-io/genson-js (multiple inputs)

Ruby:

  • https://github.com/maxlinc/json-schema-generator (1 input)
Answer from Steve Bennett on Stack Overflow
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JSON Schema
json-schema.org โ€บ tools
JSON Schema - Tools
Raise an issue to get your tool added or updated in the tooling table. Bowtie is a meta-validator for JSON Schema implementations and it provides compliance reports.
Specification [#section]
The current version is 2020-12! The previous version was 2019-09 ยท See also the release notes / change log (Work in progress)
Understanding JSON Schema
Master the full power of JSON Schema with our reference documentation. From basic data types to advanced techniques like conditional validation and schema composition, you will learn everything about JSON Schema keywords through clear explanations and examples.
Creating your first schema
After creating your JSON Schema, you can then validate example data against your schema by using a validator in a language of your choice. Please, visit Tools and select the validator that better suit your needs.
JSON Schema reference
Master the full power of JSON Schema with our reference documentation. From basic data types to advanced techniques like conditional validation and schema composition, you will learn everything about JSON Schema keywords through clear explanations and examples.
๐ŸŒ
JSON Schema
json-schema.org
JSON Schema
Adopt JSON Schema with an expansive range of community-driven tools, libraries, and frameworks across many programming languages.
๐ŸŒ
Ophir
json.ophir.dev
JSONJoy Builder - Visual JSON Schema Editor
Visual JSON Schema editor for creating and manipulating JSON Schema definitions. Open source at https://github.com/lovasoa/jsonjoy-builder
๐ŸŒ
Bjdash
bjdash.github.io โ€บ JSON-Schema-Builder
JSON Schema Builder
A simple GUI tool to enable designing and building JSON schemas.
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JSON Schema Validator
jsonschemavalidator.net
JSON Schema Validator - Newtonsoft
An online, interactive JSON Schema validator. Supports JSON Schema Draft 3, Draft 4, Draft 6, Draft 7, Draft 2019-09 and Draft 2020-12.
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Visual Studio Marketplace
marketplace.visualstudio.com โ€บ items
JSON Schema Tools - Visual Studio Marketplace
Extension for Visual Studio - Allows you to easily generate a schema file from a JSON file and generate a JSON file with dummy data based on a schema file.
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Transform
transform.tools โ€บ json-to-json-schema
JSON to JSON Schema
An online playground to convert JSON to JSON Schema
Find elsewhere
๐ŸŒ
Altova
altova.com โ€บ xmlspy-xml-editor โ€บ json_schema_editor
JSON Schema Editor and Generator | Altova
XMLSpy includes an enterprise-grade JSON Schema generator and graphical JSON schema editor that lets you create JSON Schemas, convert XSD to JSON Schema, generate JSON Schema, and even generate a JSON instance from a schema.
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GitHub
github.com โ€บ sourcemeta โ€บ awesome-jsonschema
GitHub - sourcemeta/awesome-jsonschema: A curated list of awesome JSON Schema resources, tutorials, tools, and more ยท GitHub
JSON Schema CLI - A comprehensive command-line tool for working with JSON Schema supporting formatting, linting, testing, bundling, and validation across all JSON Schema versions.
Starred by 160 users
Forked by 5 users
Languages ย  Handlebars 70.0% | JavaScript 30.0%
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GitHub
github.com โ€บ cloudflare โ€บ json-schema-tools
GitHub - cloudflare/json-schema-tools: Packages for working with JSON Schema and JSON Hyper-Schema
Packages for working with JSON Schema and JSON Hyper-Schema - cloudflare/json-schema-tools
Starred by 339 users
Forked by 30 users
Languages ย  JavaScript 100.0% | JavaScript 100.0%
๐ŸŒ
GitHub
github.com โ€บ wikimedia โ€บ jsonschema-tools
GitHub - wikimedia/jsonschema-tools: Tools to dereference and generated versioned JSONSchemas
An HTTP fileserver on top of a Git repository that contains predictable schema URLs can act much like Confluent's Avro schema registry, but with the benefits of decentralization provided by Git. $ npm i -g @wikimedia/jsonschema-tools $ jsonschema-tools --help jsonschema-tools [command] Commands: jsonschema-tools dereference Dereference a JSONSchema and output [schema-path...] it on stdout.
Starred by 24 users
Forked by 11 users
Languages ย  JavaScript 100.0% | JavaScript 100.0%
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Itential
itential.com โ€บ home โ€บ itentialโ€™s developer tools โ€บ json to json schema builder
JSON to JSON Schema - Developer Tool | Itential Network Automation
February 7, 2025 - Itentialโ€™s JSONtoSchema is a tool that intelligently and dynamically generates JSON Schema based on user provided JSON objects.
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ExtendsClass
extendsclass.com โ€บ json-schema-validator.html
Online JSON Schema Validator and Generator
This online JSON Schema Lint tool allows you to validate that your JSON document conforms to the specified schema.It uses the last release of JSON schema (draft-07).
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JSON Schema
json-schema.org โ€บ learn โ€บ getting-started-step-by-step
Creating your first schema
Now that you have your JSON Schema, it is time to validate JSON data against it using a JSON Schema Validator. A Validator is a tool that implements the JSON Schema specification.
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Schemastore
schemastore.org
JSON Schema Store
The JSON API contains a list of JSON Schema files for known JSON file formats. Each schema file can be used in tooling such as command line validators, editor auto-completion etc.
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Stoplight
docs.stoplight.io โ€บ docs โ€บ platform โ€บ zumkfdc16oypw-json-schema-editor
JSON Schema Editor | Platform
The JSON Schema Editor helps you design and model data structures used by your API. Powered by Stoplight.