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JSON Schema Validator

Q: What is the difference between required and optional fields?

In JSON Schema, all properties listed under properties are optional by default. To make a property required, list its name in the required array at the same level as properties. For example: "required": ["id", "name"] means the data must contain both id and name keys. The validator will report an error if any required field is missing, even if the value is present with the correct type.

Validate JSON data against a JSON Schema (draft-07) — instant, client-side, detailed errors

JSON Schema DRAFT-07

JSON Data TO VALIDATE

About JSON Schema Validator

JSON Schema Validator is a free, browser-based utility built for developers and engineers who need a fast, reliable way to validate json data against a json schema (draft-07) — instant, client-side, detailed errors. Whether you're debugging an API response, preparing data for deployment, or validating configuration files, this tool handles the job in seconds — with zero server calls. Everything runs locally in your browser, so your source code and data stay private.

How to Use

Enter or paste your input Type or paste your data into the input area. You can also use keyboard shortcuts (Ctrl+V) for quick pasting.

Configure options Adjust any settings or options above the input area to customize the output format and behavior.

Process your data Click the primary action button to process your input. The result appears instantly — no server round-trips.

Review the output Check the output area for your processed result. Any errors or warnings will be displayed clearly.

Copy or download Use the Copy button to copy the result to your clipboard, or download it as a file if that option is available.

🔒 Privacy note: All processing happens locally in your browser. Your data is never sent to any server.

Why Use JSON Schema Validator?

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Instant Results, Zero Setup No need to install CLI tools, configure environments, or write scripts. JSON Schema Validator gives you the result instantly in your browser — paste, click, done.

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Your Code Stays Private All processing runs locally using JavaScript. Your source code, API keys, tokens, and configuration data never leave your browser — not even temporarily.

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Part of Your Dev Workflow Bookmark this tool alongside your IDE and terminal. When you need a quick format, encode, or validation, it's one tab away — faster than installing yet another npm package.

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Use It Anywhere Works on any device with a modern browser — laptop, tablet, or phone. Perfect for quick fixes when you're away from your development machine.

Frequently Asked Questions

JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. You write a schema — itself a JSON document — that describes the expected structure, types, and constraints of your data. It is widely used for API request/response validation, configuration file validation, and documentation. The most common use is with REST APIs, where schemas define exactly what fields are required and what types they should be.

Draft-07 (2018) is the most widely supported version and is used by most libraries and tools. Draft 2020-12 is the latest stable version and adds features like $dynamicRef, prefixItems for array tuple validation, and improved unevaluatedProperties. For maximum compatibility (e.g. OpenAPI 3.0), stick with Draft-07. This validator implements the core Draft-07 keywords: type, required, properties, minimum, maximum, minLength, maxLength, enum, pattern, and items.

In JSON Schema, all properties listed under properties are optional by default. To make a property required, list its name in the required array at the same level as properties. For example: "required": ["id", "name"] means the data must contain both id and name keys. The validator will report an error if any required field is missing, even if the value is present with the correct type.