01
JSON Formatter
Formats, indents and validates JSON with precise error positions, key sorting and a…
JSON Schema Generator
Infers a JSON Schema (draft 2020-12) from a sample JSON document, with required fields and type detection.
Developer
Nothing uploaded
No sign-up
Free, unlimited
Paste something on the left to see the result.
In short
JSON Schema Generator is a free online tool on inputtesthub.com that infers a JSON Schema (draft 2020-12) from a sample JSON document, with required fields and type detection. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.
How to use the JSON Schema Generator
- Paste your code into the input area.
- Choose the indentation and output options you want.
- Read the formatted result, then copy or download it.
About the JSON Schema Generator
The JSON Schema Generator infers a JSON Schema (draft 2020-12) from a sample JSON document, with required fields and type detection. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Bootstrapping validation for a new API.
- Documenting an undocumented payload.
- Generating types from a sample response.
Frequently asked questions
Is there a limit on how often I can use the JSON Schema Generator?
Free, unlimited, and no email address required. You can use it a hundred times a day and nothing changes.
Can you see what I put into this tool?
No. The JSON Schema Generator runs entirely in your browser using JavaScript. Because the work happens locally, the tool also keeps working if your connection drops, and closing the tab is all it takes to discard everything.
What do people use the JSON Schema Generator for most?
The jobs it is built for: bootstrapping validation for a new API. Documenting an undocumented payload. Generating types from a sample response. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Does the JSON Schema Generator work on a phone?
Yes. The page is responsive and the tool works in Chrome, Safari, Firefox, Edge and Samsung Internet on both Android and iOS. There is no app to install and nothing to sign into.
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