JSON Validator
Frequently Asked Questions
What is the difference between JSON validation and JSON formatting?
JSON validation checks whether your JSON is syntactically correct according to the RFC 8259 standard — confirming it can be parsed without errors. JSON formatting arranges valid JSON with consistent indentation for readability. Validation must pass before formatting is meaningful; formatting does not fix syntax errors.
Why does my JSON fail even though it looks correct?
The most common hidden causes are trailing commas after the last item in an object or array, single quotes instead of double quotes, smart quotes pasted from word processors, unescaped backslashes or newlines inside strings, and JavaScript-only values like undefined or NaN that are not part of the JSON specification.
Is my data safe when I use this JSON Validator?
Yes. All validation runs entirely in your browser using native JSON.parse() — no data is sent to any server. This makes it safe to paste API keys, personal data, or proprietary configurations without any privacy risk. No logs, no storage, and no network requests are made during validation.
Can this validator check JSON Schema compliance?
No. This tool validates JSON syntax only — confirming the text is well-formed and parseable. JSON Schema validation, which verifies that values match required types and constraints defined in a schema, is a separate process best handled by libraries like AJV in JavaScript or jsonschema in Python.
What JSON specification does this validator follow?
This tool uses the browser native JSON.parse() which follows the ECMAScript specification, closely aligned with RFC 8259 — the official JSON standard. This is the same parser used by Node.js, Chrome, and all major JavaScript runtimes, so validation results match real-world parsing behaviour exactly.
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