Validate your JSON data and find errors
Valid JSON is critical for applications, APIs, and configuration files to function correctly. A single misplaced comma, missing bracket, or unquoted key can cause an entire application to fail. NewToolSuite's JSON Validator instantly checks your JSON data for syntax errors and reports exactly where problems occur, helping you fix issues before they reach production.
The validator checks for all common JSON errors including mismatched brackets and braces, trailing commas, unquoted keys, single-quoted strings (which are not valid JSON), incorrect escape sequences, and malformed numbers. When errors are found, the tool provides a clear description of the problem and its location in the data, making debugging fast and straightforward.
This tool is essential for developers working with REST APIs, NoSQL databases like MongoDB, configuration files for tools like package.json or tsconfig.json, and any system that consumes JSON data. It runs entirely in your browser with no data transmitted externally, making it safe for validating sensitive configuration data, API keys, and private information.
It detects syntax errors including mismatched brackets, trailing commas, unquoted keys, invalid escape sequences, and malformed values.
Standard JSON does not support comments. The validator follows the official JSON specification (RFC 8259). JSON with comments (JSONC) is a different format.
The validator checks against the standard JSON specification. Extended formats like JSON5 or JSONC have different rules.
No fixed limit. The validator handles large JSON documents, constrained only by your browser's memory.
The validator identifies errors and their locations so you can fix them manually. Automatic repair is not possible because the intended structure may be ambiguous.