JSON Validator Online
Validate JSON data instantly. Find syntax errors, get line numbers, and fix issues. 100% private — everything runs in your browser. No login required.
Input JSON 0 chars
Output
Why Validate JSON?
Catch Errors Before Deployment
Invalid JSON breaks APIs, configs, and applications. Validating before deployment prevents production errors that can take down services and frustrate users.
Debug API Responses
When an API returns unexpected results, validate the response JSON to find formatting errors. Our validator shows exact line numbers to speed up debugging.
Ensure Data Integrity
Configuration files, data exports, and integrations all depend on valid JSON. Validate data at every stage to ensure it meets the JSON specification and won't cause downstream errors.
Frequently Asked Questions
What does JSON validation check?
JSON validation checks for syntax errors including missing brackets, unclosed strings, trailing commas, invalid escape sequences, duplicate keys, and malformed values. Our validator shows the exact line number and error description for each issue found.
How do I fix JSON errors?
Our validator shows line numbers and error descriptions for every issue. Common fixes include: adding missing closing brackets, removing trailing commas, escaping special characters in strings, and ensuring all strings are wrapped in double quotes.
What's the difference between validate and beautify?
Validate checks your JSON for syntax errors and reports any issues found. Beautify formats your JSON with proper indentation and line breaks for readability. Validation tells you if something is wrong; beautification makes valid JSON easier to read.
Is my JSON sent to a server?
No. All JSON validation happens in your browser. Your data never leaves your device.