JSON Schema Validator & Formatter
指导
JSON Schema Validator & Formatter
Validate your JSON data against a JSON Schema with precise, detailed error reporting. Paste your data and schema, select the draft version, and get instant feedback — including exact JSON Pointer paths to every validation error. All processing runs client-side, so your data never leaves your browser.
如何使用
Paste your JSON data in the first textarea and your JSON Schema in the second. Select the schema draft version (draft-07, 2019-09, or 2020-12) and click Validate. The tool displays a clear pass or fail result with detailed error messages showing the exact path, violated keyword, and explanation for each issue. Use the Format buttons to beautify either input.
特征
- Multiple Schema Drafts – Supports JSON Schema draft-07, draft-2019-09, and draft-2020-12 via the ajv validation library.
- Detailed Error Reporting – Each validation error shows the JSON Pointer path to the offending value, the violated keyword, and a human-readable error message.
- JSON Beautifier – Format and pretty-print both your JSON data and schema with proper indentation for easier reading and editing.
- 客户端处理 – All validation runs in your browser using the industry-standard ajv library. No data is sent to any server.
- Example Data – Try the built-in example to see how validation works before pasting your own data.
何时使用此工具
Use this tool when building or debugging APIs that use JSON Schema for request validation, testing configuration files against their schemas, or verifying that sample data conforms to a specification. It’s especially useful for catching subtle issues — missing required fields, type mismatches, or pattern violations — that are easy to miss by eye but break applications at runtime.
常问问题
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What is JSON Schema and what is it used for?
JSON Schema is a vocabulary that lets you annotate and validate JSON documents. It defines the expected structure, types, and constraints of JSON data — like which fields are required, what types they should be, and what patterns strings must match. It's widely used for API request/response validation, configuration file validation, and data interchange specifications.
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What is the difference between JSON Schema draft-07, 2019-09, and 2020-12?
Each draft adds new keywords and refines existing behavior. Draft-07 is the most widely supported and includes keywords like if/then/else. Draft-2019-09 added vocabularies, unevaluatedProperties, and dependentRequired. Draft-2020-12 refined dynamic references and prefixItems (replacing the array form of items). Most tools support draft-07; newer drafts offer more expressive power but have slightly less universal tooling support.
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What is a JSON Pointer path in validation errors?
A JSON Pointer is a string syntax for identifying a specific value within a JSON document (defined in RFC 6901). It uses forward slashes to navigate into objects and arrays — for example, /users/0/email points to the email field of the first user in a users array. Validation errors include these paths so you can pinpoint exactly where in your data the problem occurs.
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What is ajv and why is it the standard for JSON Schema validation?
Ajv (Another JSON Validator) is the most widely used JSON Schema validator for JavaScript. It supports all major drafts, compiles schemas into optimized validation functions for speed, and provides detailed error reporting. It's used by major projects including webpack, ESLint, and the OpenAPI toolchain, processing billions of validations daily.
