JSON Schema Validator & Generator
Validate JSON with pointer-based errors or generate a draft 2020-12 starter schema from sample data.
Run validation to compare the instance with the schema.
Input stays in this browser. This focused validator supports common structural keywords; use a full standards validator for dynamic references, vocabularies, and custom formats.
Instance and schema inputs stay in your browser. The validator implements a focused subset of common structural keywords; it does not claim complete JSON Schema conformance.
Overview
Validate JSON instances with JSON Pointer errors and generate a draft 2020-12 starter schema from sample JSON in your browser.
Start with one of the included examples, inspect every finding, and verify consequential changes against the linked primary documentation and your own environment.
Use cases
When to use it
- Example 1.Validate an API response against required fields, types, string rules, ranges, arrays, and additionalProperties.
- Example 2.Generate a reviewable starter schema from a representative JSON sample.
When it's not enough
- Production guarantees.A point-in-time tool result cannot prove every runtime, resolver, client, or edge location behaves the same way.
- Blind automation.Review generated output and findings before committing configuration or security changes.
How to use it
- 1
Load or paste a representative input
Validate an API response against required fields, types, string rules, ranges, arrays, and additionalProperties.
- 2
Run the focused checks
Read the exact path, record, operation, or certificate field attached to each finding.
- 3
Verify and apply
Use JSON Schema validation errors and fixes and the related tools to confirm the fix before release.
Common errors and fixes
The input is incomplete or malformed
Reduce it to the smallest reproducible sample, correct the parse error, and rerun the check.
The tool passes but production still fails
Compare environment-specific inputs, network vantage points, versions, caches, and full standards conformance.