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JSON Schema Workbench

Compile Draft 7, 2019-09, or 2020-12 JSON Schemas in an isolated worker and validate bounded instance data with precise evidence.

LocalNo input retention

Reviewed July 13, 2026

Guide, examples, and validation Show

About this tool

Separate schema compilation problems from instance validation errors and review the exact instance pointer, schema path, and keyword for every issue.

  • Uses separate Ajv validators for Draft 7, 2019-09, and 2020-12 inside a disposable, five-second Web Worker.
  • Rejects non-strict JSON, duplicate keys, unsafe integers, oversized or deeply nested documents, and unresolved remote $ref values without fetching them.
  • Exports a report without full input source, including metrics, status, keyword, JSON Pointer, schema path, draft evidence, and bounded errors.

How to use Schema Workbench

Paste or load a JSON Schema and instance, validate both documents, then review paths, keywords, and messages in the report before exporting it.

When this tool is useful

  • Testing an API example against a local schema.
  • Reviewing schema changes without fetching remote references.

Practical tips

  • Use explicit local schemas because remote $ref loading is disabled.
  • Test valid, invalid, missing, and boundary examples.

Examples you can test

Load an example, compare the result with the expected output, then replace it with your own input.

Require an integer identifier

Example input

Schema requires integer id; instance contains id as a string

Expected output

Type error at /id

Fix the instance or schema intentionally rather than coercing silently.

Validation checklist

  • Confirm the intended schema draft and formats.
  • Resolve every reported instance path.
  • Retest a known-valid example.

Frequently asked questions

Does this fetch remote $ref schemas?

No. Remote reference loading is disabled, so validation does not send schema URLs or instance data to another server.

Which JSON Schema drafts are supported?

Choose Draft 7, 2019-09, or 2020-12. The declared $schema URI is detected separately so a mismatch remains visible.

Are format values validated?

Common formats are asserted using ajv-formats. The report states the selected draft and validation scope.

What limits protect the browser?

Schemas are limited to 500,000 characters, instances to 1,000,000 characters, and files to 2,000,000 bytes. Each document is limited to 100,000 value nodes and 128 levels, up to 200 errors are returned, and validation stops after five seconds.

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