JSON Validator

Paste your JSON into the input area. The validator checks it instantly and shows a green success indicator if the JSON is valid. If there are errors, the problematic lines are highlighted and a detailed error message explains exactly what is wrong and where.

The validator catches all JSON syntax errors including: missing or extra commas, unquoted property names (keys must be in double quotes), trailing commas after the last item, mismatched brackets or braces, single quotes instead of double quotes, and missing colons between keys and values.

JSON validation checks whether your JSON is syntactically correct — it can be parsed without errors. JSON formatting (beautifying) adds indentation and whitespace for readability. Validation is a pass/fail check; formatting is a presentation enhancement. Our tool validates first, then formats valid JSON.

Yes. Copy the API response body (even if it is compact or minified) and paste it into the validator. The tool checks for validity and optionally formats it for easier reading. This is especially useful when debugging API integrations or inspecting webhook payloads.

Yes. The validator can handle large JSON files (hundreds of kilobytes) since it uses JavaScript's built-in JSON.parse() function which is highly optimized. Very large files (several megabytes) may take a moment to process depending on your device's processing power.

The current tool validates JSON syntax (whether the JSON can be parsed). JSON schema validation — checking whether values conform to a specific data schema — requires a separate schema validation step. For schema validation, use a dedicated JSON schema validator with your schema definition.

No. JSON validation uses JavaScript's native JSON.parse() function running entirely in your browser. Your JSON data, API keys, configuration secrets, or any other content you paste are never transmitted to any server or third party.

Yes. The JSON Validator is fully mobile-responsive. Open the tool in any mobile browser, paste your JSON (from clipboard or by typing), and the validation result appears instantly.

Common hidden issues include: invisible special characters (copy-paste sometimes introduces zero-width spaces), Windows line endings causing encoding issues, or a JSON string containing unescaped special characters like backslashes or quotes. Try re-typing the problematic section manually.

Yes. Completely free, no sign-up, no usage limits, and no file size restrictions. Validate as much JSON as you need, whenever you need it.