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JSON Formatter

Format, prettify, and minify JSON with validation.

Documentation & User Guide

JSON Formatter & Validator Guide

JSON (JavaScript Object Notation) is the standard format for exchanging structured data in modern web APIs and configuration files. Because raw API responses are often minified (compacted without spaces or line breaks) to save bandwidth, they are difficult for humans to read. The JSON Formatter takes raw, minified, or malformed JSON strings, validates their syntax, and outputs clean, indented, syntax-highlighted code.

⚙️ Key Features

  • Formats and beautifies minified JSON with customizable spacing (2 or 4 spaces).
  • Identifies exact syntax errors (like missing quotes, trailing commas) with line number highlights.
  • Interactive tree view layout to browse deeply nested arrays and objects with collapsible segments.
  • Supports minification to strip whitespace and optimize JSON payloads for storage or transmission.

📖 How to Use

  1. Type or paste your raw JSON string into the editor box, or upload a JSON file.
  2. The editor will instantly highlight syntax errors if the structure is invalid.
  3. Click 'Prettify' to align lines and indent according to your settings, or click 'Minify' to compress it.
  4. Use the 'Show tree view' toggle to inspect values, collapse arrays, and browse keys interactively.
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Privacy & Security:

Formatting, minification, and tree building happen entirely within your local browser's JavaScript runtime. Your JSON data never leaves your computer.

Frequently Asked Questions (FAQ)

Why is a trailing comma invalid in JSON?

According to the JSON specification (RFC 8259), trailing commas are strictly prohibited after the last element in an array or the last property in an object. This is a common syntax error.

Does the formatter support comments?

Standard JSON does not support comments (// or /* */). However, our formatter will attempt to parse and clean up comments if present, though they will be removed during strict validation.

Can this tool format extremely large files?

Yes, our optimized renderer can process JSON payloads up to several megabytes quickly inside the browser without locking up your screen.