Beautify, validate, minify, and inspect JSON with syntax error detection and tree preview.
Validate nested JSON payloads, format with 2 or 4 spaces, remove whitespace for production minification, and catch line-specific syntax errors.
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The JSON Formatter & Validator parses raw or minified JSON strings, validates them against strict RFC 8259 syntax specifications, and formats them with consistent hierarchical indentation, syntax highlighting, and actionable diagnostic errors. In modern software engineering, JSON (JavaScript Object Notation) is the universal format for RESTful APIs, configuration files, and document databases. When inspecting compact or machine-generated API payloads, formatting unescapes nested structures and makes identifying missing keys, type mismatches, or malformed data straightforward.
Paste ugly, minified, or single-line JSON responses from network tabs or curl commands to inspect keys with clear indentation.
Example: Formatting a raw Stripe or GitHub webhook response to examine nested error codes and timestamps.
Identify missing commas, unescaped quotes, or illegal trailing commas that break backend parsing in Node.js or Python.
Example: Locating an illegal trailing comma on line 42 that was causing a server 500 error.
Format `package.json`, `tsconfig.json`, or settings files with clean 2-space or 4-space indentation for git commits.
Example: Cleaning up a messy `settings.json` file for inclusion in an open-source repository.
Standard JSON supports exactly six data types: 1) Strings (enclosed in double quotes); 2) Numbers (integers or floating-point, without NaN/Infinity); 3) Booleans (`true` or `false`); 4) Null (`null`); 5) Arrays (ordered lists `[...]`); and 6) Objects (unordered key-value collections `{...}`). Unsupported types like `undefined`, functions, or circular references cannot be represented in valid JSON.
The most frequent JSON errors are: 1) Using single quotes instead of double quotes for strings and keys; 2) Leaving a trailing comma after the last item in an array or object; 3) Forgetting escape backslashes before internal quotation marks or control characters; and 4) Missing or mismatched closing brackets (`}` or `]`).
Standard RFC 8259 JSON does not permit comments (`//` or `/* */`). While JSON5 and JSONC variants allow comments, strict JSON parsers will reject payloads containing comment syntax.
Validating checks whether a text string adheres strictly to JSON syntax rules. Formatting (pretty-printing) adds line breaks and indentation spaces so humans can read and debug data structures easily. Minifying strips all extraneous whitespace outside of string values to reduce payload size for high-speed network transmission.
No. The validation and formatting engine runs entirely inside your browser sandbox using native JavaScript JSON functions without transmitting data to any server.