Validate JSON syntax instantly with our free online JSON validator. Check for malformed JSON, missing brackets, trailing commas, and invalid data types. Get precise error messages with line and column numbers. 100% client-side.
Our JSON Validator is a free online tool that checks your JSON data for syntax errors and structural issues. It provides detailed error messages with exact line and column numbers, helping you quickly identify and fix problems in your JSON files. All validation happens entirely in your browser — your data never leaves your device.
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write and easy for machines to parse and generate. It is based on a subset of the JavaScript programming language and is widely used for data storage, configuration files, and API responses.
Our validator uses the built-in JSON.parse() method combined with custom error parsing to provide detailed feedback. It catches all standard JSON syntax errors including missing brackets, trailing commas, invalid escape sequences, and malformed values.
Absolutely. All validation happens entirely in your browser. No JSON data is sent to any server or stored anywhere. Your data remains completely private.
Yes, you can validate large JSON files. The tool processes JSON entirely in your browser, so the limit depends on your device memory. Most modern browsers can handle JSON files up to several megabytes.
Our validator catches common errors such as trailing commas after the last element in objects or arrays, missing quotes around keys, invalid escape sequences, unclosed brackets, and invalid data types. It also provides the exact line and column where each error occurs.