JSON (JavaScript Object Notation) is a lightweight, text-based data format used for data exchange between systems. It's popular because it's human-readable, language-independent, and easy to parse. JSON is widely used in web APIs, configuration files, and data storage.

Simply paste your JSON data into the JSONLinter validator above and it will automatically check for syntax errors, missing brackets, invalid characters, and other common issues. The validator provides instant feedback with line numbers for any errors found.

Yes! JSONLinter is completely free to use with no signup required. You can validate, format, and beautify unlimited JSON data directly in your browser. All processing happens client-side, so your data never leaves your computer.

JSON validation checks if your data follows proper JSON syntax rules (correct brackets, quotes, commas, etc.). JSON formatting (or beautifying) takes valid JSON and makes it more readable by adding indentation and line breaks. JSONLinter does both automatically.

Yes, JSONLinter can handle large JSON files efficiently. Since all processing happens in your browser, performance depends on your device. For very large files (>10MB), you may experience slower performance depending on your system.

When JSONLinter detects an error, it shows the line number and describes the issue. Common fixes include: adding missing quotes around property names, removing trailing commas, ensuring all brackets and braces are properly closed, and escaping special characters in strings.

Absolutely! JSONLinter processes all data locally in your browser. Your JSON data is never sent to any server or stored anywhere. You can even use the tool offline once the page has loaded.

Common mistakes include: using single quotes instead of double quotes, adding trailing commas after the last item, forgetting to quote property names, not escaping special characters in strings, and using undefined or functions (which aren't valid in JSON).