JSON Formatter & Validator

The JSON Formatter & Validator beautifies, minifies and validates JSON. Paste minified or messy JSON and the tool indents it consistently so you can read the structure at a glance. Paste pretty JSON and click Minify to strip whitespace for compact transmission. And if your JSON has a syntax error — a missing comma, an unquoted key, a trailing bracket — the tool pinpoints the problem instead of leaving you to hunt.

JSON (JavaScript Object Notation) is the data interchange format of the modern web. APIs return it, configuration files use it, databases store it, and logs are full of it. But JSON in the wild is often minified (to save bandwidth) or machine-generated (with inconsistent formatting), which makes it hard to read. A reliable formatter turns a wall of text into a navigable, indented tree.

This tool uses the browser's native JSON.parse for validation, which is strict and matches the RFC 8259 specification exactly. When parsing fails, the error message includes the position of the problem so you can jump straight to the issue. Formatting uses JSON.stringify with a configurable indentation (2 spaces, 4 spaces, or tabs). Minify mode produces the smallest valid JSON — no whitespace, ideal for API payloads and storage.

Common use cases: inspecting an API response, debugging a config file, cleaning up generated JSON, preparing a payload for a request, and learning JSON syntax. Everything runs locally in your browser — your JSON never leaves your device, which matters when you are working with API keys, credentials or sensitive payloads.