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JSON Schema Validator

Validate a JSON document against a draft-07 schema and see every failure by path.

Quick Tool Overview

The JSON Schema Validator checks a document against a draft-07 schema and reports every failure with the path that failed and the rule it broke, rather than one vague message about the whole file.

What it does
Validates a JSON document against a JSON Schema
You give it
A draft-07 schema and a document to check
You get back
Every failure, with its path and the rule it broke
Best for
Contract testing, config validation and API integration work
Developer Tools Free, unlimited use No sign-up Runs in your browser

About the JSON Schema Validator

Syntax validation only tells you a document parses. Schema validation tells you it is the right document: the fields you need are present, the types are what you expect, the numbers are in range and the strings match their patterns.

Paste a schema and a document and every failure is listed with the path that failed and the rule it broke, rather than one vague message about the whole file. The supported keyword set is the one hand-written schemas use: type, required, properties, patternProperties, additionalProperties, items, enum, const, minimum and maximum with their exclusive forms, multipleOf, minLength, maxLength, pattern, format, minItems, maxItems, uniqueItems, minProperties, maxProperties, allOf, anyOf, oneOf, not, and local $ref pointers.

Key features of the JSON Schema Validator

Failures are located

Each error names the path, such as $.items[2].price, and the constraint it violated — not just that the document is invalid.

All the keywords a hand-written schema uses

type, required, properties, patternProperties, items, enum, const, numeric and string bounds, uniqueItems, allOf, anyOf, oneOf, not and local $ref.

Format checking

date, time, date-time, email, hostname, ipv4, ipv6, uri and uuid are checked; unknown formats are accepted and ignored as the spec allows.

Both boxes are live

Edit the schema or the document and validation re-runs immediately, which makes tightening a schema an interactive process.

No network access

Remote $ref URLs are not fetched by design. Local pointers resolve normally, so inline your definitions and nothing leaves the tab.

How to use the JSON Schema Validator

  1. 1

    Paste your schema

    A draft-07 JSON Schema goes in the schema box.

  2. 2

    Paste the document

    The JSON you want checked goes in the document box.

  3. 3

    Read the failures

    Each one names the path and the rule, so you know which field and which constraint.

  4. 4

    Fix and re-check

    Both boxes are live, so corrections re-validate as you type.

Frequently asked questions

Draft-07 and the keywords it shares with later drafts. That covers essentially every hand-written schema; the 2020-12 dynamic reference keywords are not implemented.

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