User Guide
Overview
The JSON Validator checks whether your JSON is syntactically valid and highlights errors when it is not.
JSON must follow strict rules. A missing quote, extra comma or mismatched bracket can break an API request or cause an application to fail. This tool lets you validate JSON quickly before using it in code, configuration files or data pipelines.
Use it when you want a fast answer to one question: is this JSON valid or not.
When to Use This Tool
- An API request fails due to malformed JSON
- You are editing JSON by hand and want to confirm correctness
- A configuration file will not load
- You receive JSON from an external source and want to sanity-check it
- You want to validate data before formatting or further processing
If you need to reformat valid JSON, use our JSON Formatter tool to beautify or minify your code.
How to Use the Validator
- Paste or type your JSON into the input field above
- Click Validate
- Review the validation result and any error messages
The validator runs entirely in your browser.
Example
Valid JSON
{
"name": "John Doe",
"age": 30,
"isMember": true
}This input will return a successful validation result.
Common Validation Errors
If your JSON is invalid, the validator will indicate an error. Common issues include:
- Missing double quotes
JSON requires double quotes around keys and string values - Trailing commas
Commas after the last item in an object or array are not allowed - Mismatched brackets or braces
Every { must have a matching } and every [ must have a matching ] - Invalid values
Only valid JSON values are allowed: strings, numbers, objects, arrays, true, false and null
Fix the reported issue and validate again.
Limitations and Notes
- This tool validates JSON syntax only
- It does not enforce schemas or data shape rules
- It does not format or modify the input
To validate structure or required fields, use a JSON Schema Validator.