Format, validate, and minify JSON instantly. Runs entirely in your browser.
JSON (JavaScript Object Notation) is a lightweight, human-readable data format used for storing and exchanging structured data. It uses key-value pairs and nested arrays to represent complex information in a text format that both humans and machines can easily parse.
JSON is the standard format for REST APIs, configuration files (package.json, tsconfig.json), and data interchange between services. Nearly every programming language has built-in JSON support, making it the universal language of modern web development.
Validating JSON before use catches syntax errors like missing commas, trailing commas (not allowed in strict JSON), unquoted keys, or mismatched brackets. This tool highlights errors with exact line and column positions, and provides syntax highlighting so you can quickly spot structural issues. Everything runs client-side — your data never leaves your device.
It takes raw or minified JSON, validates its structure, and outputs a neatly indented and syntax-highlighted version for easy reading.
The formatter validates JSON and highlights errors but does not auto-fix structural problems. You will need to correct syntax errors like missing commas or brackets.
No. All formatting and validation happens locally in your browser. Your data stays on your device.
APIs, config files, and webhook payloads are often delivered minified on one line. This browser-side formatter pretty-prints, validates, and minifies JSON so you can spot structural errors — missing commas, unquoted keys, trailing commas — without uploading sensitive payloads to a remote server.
package.json-style filesValid JSON will format with consistent indentation and highlight structure. Errors usually report near the first unexpected token: a trailing comma after the last property, single quotes instead of double quotes, or a truncated payload from a log line. Minify only after the document validates — minifying broken JSON just hides the problem.
A webhook integration failed with a generic parse error. Pasting the body here showed a trailing comma after the last field — legal in modern JavaScript, illegal in strict JSON. Removing the comma fixed the consumer without changing the producer’s schema.
Processing stays in your browser; we do not store payloads. Extremely large documents may be limited by browser memory. This tool does not transform JSON Schema, YAML, or XML — only JSON text.