Validate JSON data for syntax errors instantly. Free online JSON validator with detailed error messages.
Want to jump straight in? Use our free JSON Validator tool directly.
Navigate to the JSON Validator tool on UtilsNow. It runs entirely in your browser for privacy.
Copy your JSON string and paste it into the input area. The tool accepts any size of JSON data.
The tool instantly validates your JSON and shows either a success message or a detailed error with the line number and position of the issue.
If errors are found, the tool highlights the exact location of the problem and suggests how to fix common issues like missing commas or brackets.
Once your JSON is valid, copy the cleaned version or download it as a file.
Use our free JSON Validator tool — no signup, no uploads, works directly in your browser.
Open JSON ValidatorIt detects missing commas, unclosed brackets, trailing commas, invalid escape sequences, duplicate keys, and all other JSON syntax violations.
The tool validates JSON syntax. For schema validation (JSON Schema), use the JSON Formatter which offers more advanced options.
No. Since validation happens locally in your browser, there is no server-imposed size limit.