JSON Validation: How to Validate and Fix JSON Data
Learn how to validate JSON data, common JSON errors, and how to use online validators to detect and repair invalid JSON.
Jun 23, 2026
JSON Schema Validator
Validate your JSON data against a JSON Schema instantly.
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Validation Failed
Valid!
The JSON data is valid against the schema.
Invalid Schema
What is JSON Schema?
JSON Schema is a declarative language that allows you to annotate and validate JSON documents. It describes the shape of your JSON data — what fields are expected, what types they should be, which values are required, and more.
Using JSON Schema, you can define constraints such as:
- Data types:
string,number,integer,boolean,array,object - String patterns, min/max length, enum values
- Numeric ranges (minimum, maximum, exclusiveMin, exclusiveMax)
- Required properties, additional properties
- Nested and conditional schemas (
if/then/else,allOf,anyOf,oneOf)
How to Use
- Paste your JSON Schema — Enter a valid JSON Schema in the left textarea. You can use the Load Example button to see a working example.
- Paste your JSON Data — Enter the JSON data you want to validate in the right textarea.
- Validate — Click Validate to check if your data conforms to the schema. Results appear instantly below.
- Review errors — If validation fails, each error shows the JSON Pointer path, the schema rule that was violated, and a human-readable message.
Frequently Asked Questions
What JSON Schema draft versions are supported?
This tool supports JSON Schema draft-07 by default. It also works with draft-04, draft-06, and draft 2019-09 schemas. You can specify the version using the $schema keyword in your schema.
What is the difference between JSON Validator and JSON Schema Validator?
JSON Validator checks if a JSON string is syntactically valid (correct JSON syntax). JSON Schema Validator goes further — it checks if your JSON data matches a specific structure and constraints defined in a JSON Schema. A JSON document can be syntactically valid but not conform to a given schema.
Is this tool safe for sensitive data?
Yes. All processing happens entirely in your browser using JavaScript. Your JSON data and schema are never uploaded to any server, stored in any database, or logged.
Last updated: 17 Aug 2026