JSON Formatter & Validator

JSON (JavaScript Object Notation) is a lightweight data format used extensively in web development, APIs, and configuration files. Formatting JSON means adding proper indentation and line breaks so the structure is easy to read. Minified JSON removes all unnecessary whitespace to reduce file size, which is useful when transmitting data over a network. This tool lets you switch between human-readable and compact formats instantly, making it easier to debug API responses, inspect configuration files, or prepare data for production use.

Paste raw or minified JSON into the input field and click Format to pretty-print it with your chosen indentation level (2 spaces, 4 spaces, or tabs). Click Minify to strip all whitespace for a compact single-line output. The Validate button checks whether your input is syntactically valid JSON and reports the exact error location if something is wrong. You can also load a sample to see the tool in action. Everything runs in your browser using native JavaScript parsing, so your data never leaves your machine.

When debugging malformed JSON, pay attention to common mistakes like trailing commas after the last item in an array or object, single quotes instead of double quotes, and unescaped special characters in strings. If you are working with large API responses, use the Format button first to visualize the structure, then copy specific nested objects for further inspection. For production deployments, always minify your JSON configuration files to reduce payload size and improve load times. If your workflow involves encoding JSON for transport, try our Base64 Encoder/Decoder. You can also use our Diff Checker to compare two JSON documents and spot changes quickly.