JSON Validator
Validate, format, and minify JSON data with real-time error detection and syntax highlighting. Runs in your browser.
Paste JSON or drop a .json file, , or start from an example:
The check, formatted output and tree appear below as you paste.
Runs locally in your browser; your JSON is only saved in this browser so it survives a reload.
Frequently Asked Questions
What is JSON and why do I need to validate it?
JSON (JavaScript Object Notation) is a lightweight data format used for storing and exchanging data. Validation ensures your JSON is properly formatted with correct syntax, preventing errors when used in applications or APIs.
What types of JSON errors can this validator detect?
Our validator detects syntax errors like missing quotes, brackets, or commas, invalid escape sequences, and improper data types. It shows the line and column where errors occur.
Can I format minified JSON?
Yes! The Format button will beautify any valid JSON with proper indentation and line breaks. You can choose between 2 spaces, 4 spaces, or tabs for indentation.
Is my JSON data secure?
Absolutely. All validation happens directly in your browser. No data is sent to any server. Your JSON remains completely private and secure on your device.
What's the maximum file size I can validate?
The validator can handle large JSON files up to several megabytes. For very large files, validation may take a moment. The tool uses efficient algorithms to process even complex nested structures quickly.