Calculator
What the JSON Schema Generator does
JSON Schema Generator: generates Status and JSON Schema from JSON sample, Schema title and additionalProperties. Example: schema title Generated schema and additionalproperties Leave open (default) gives status Draft-07 schema with 10 typed nodes.
Supply JSON sample, Schema title and additionalProperties and you get Status and JSON Schema back. Edit a field and the answer updates in place.
Typical users are developers debugging a payload. Spotting a malformed field is far quicker when the structure is laid out clearly.
Everything happens inside this page. Nothing you type is sent to a server, and there is nothing for us to store.
The rest of this page documents each field, the method, and a worked example built from the values the JSON schema generator loads by default.
What do the JSON Schema Generator fields mean?
The JSON Schema Generator uses 3 inputs. You can work from the defaults, or clear them and start fresh, both work.
| Field | What to enter | Default |
|---|---|---|
| JSON sample | paste or type any amount of text | { "id": 42, "email": "ada@example.com", "created": "2026-09-08T10:00:00Z", "score": 4.5, "tags": ["a", "b"], "profile": { "city": "London", "verified": true } } |
| Schema title | optional | Generated schema |
| additionalProperties | choose from Leave open (default) or false (strict objects) | Leave open (default) |
How does the JSON Schema Generator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same generated output.
The guard clauses run before the formula does, which is why mistakes surface next to the field.
Worked example
These are the values the JSON Schema Generator loads by default, and the result it produces from them. Here is the calculation as it stands the moment the page loads.
| JSON sample | { "id": 42, "email": "ada@example.com", "created": … |
|---|---|
| Schema title | Generated schema |
| additionalProperties | Leave open (default) |
| Status | Draft-07 schema with 10 typed nodes |
|---|---|
| JSON Schema | { "$schema": "http://json-schema.org/draft-07/schema#", "title": "Generated schema", "type": "object"… |
Read next: JSON Schema Validation: A Practical Guide
How to use it
- Paste your content into JSON sample.
- Key in Schema title.
- Pick a value for additionalProperties: the options are Leave open (default) or false (strict objects).
- The tool reacts immediately rather than waiting for you to finish the form.
- The results panel then shows Status and JSON Schema.
- Copy Link is the quickest way to send the exact scenario to someone else.
What this tool does not do
- Output follows the common convention for this format; a specific toolchain may have its own house style.
- Processing happens in your browser, so very large inputs are bounded by available memory.
- The result reflects the moment you ran it; anything that changes over time is not tracked.
Frequently asked questions
JSON sample, Schema title and additionalProperties. That is the whole form. Nothing starts empty, meaning you can explore the calculation before committing to real figures.
With the values loaded when the page opens, status comes out as Draft-07 schema with 10 typed nodes. Any edit re-runs the calculation, so there is no stale number on screen.
Nothing is logged. The tool is client-side code; your data stays where you entered it.
Nothing at all. There is no registration, no paywall and no per-use quota.
Reliable for the case described. Where more than one convention exists, the method section says which one is used.