Quick take
Check JSON against a schema and see which field failed.
- Validate an API response before handing it to a frontend team.
- Find a missing required field in a webhook payload.
JSON Schema Validator
live
Not validated
| Path | Issue | Expected | Actual |
|---|---|---|---|
| No validation errors to show. | |||
Where it fits
Use JSON Schema Validator for checking API payloads, config objects, fixtures, and generated JSON against expected rules. It works well when you want validation pass or failure details that identify rule violations and do not need a bigger workflow around it.
- Best fit: checking API payloads, config objects, fixtures, and generated JSON against expected rules.
- You start with JSON data plus a JSON Schema.
- The useful choices are required fields, type rules, enum values, nested schemas, and draft compatibility.
- Check missing required properties, wrong value types, extra fields, and array item rules.
- You end up with validation pass or failure details that identify rule violations.
What the page is actually doing
- JSON data and schema are parsed locally.
- The validator supports common JSON Schema rules such as type, required, properties, items, enum, const, length, numeric bounds, and pattern.
- Remote $ref values are not fetched.
A clean way to use JSON Schema Validator
- Start with JSON data plus a JSON Schema.
- Choose required fields, type rules, enum values, nested schemas, and draft compatibility.
- Run the tool once, then review missing required properties, wrong value types, extra fields, and array item rules.
- Copy, export, or download validation pass or failure details that identify rule violations.
- Compare the final output against one known-good sample before you move on.
Where mistakes happen
- JSON Schema draft support can differ across validators, especially for newer conditional and composition keywords.
- A schema should model the contract that matters, not every incidental field from one sample.
- Start with required fields and key types, then add stricter rules after the basic contract is stable.
- Keep example valid and invalid payloads beside the schema for future review.
How your data is handled
This tool works in your browser. Toolumina does not upload or keep the content you enter here.
FAQ
Which JSON Schema draft is supported?
This tool supports the Draft 7 features most teams use for day-to-day validation work.
Does it fetch remote $ref schemas?
No. Remote references are intentionally not fetched for privacy and security.
Can it generate a schema?
Yes. The Generate basic schema action creates a starter schema from the current JSON value.