What is JSON formatting?

JSON formatting (or beautifying) adds indentation, line breaks, and consistent spacing to minified or poorly formatted JSON data, making it human-readable. Minification does the reverse — removes all whitespace to reduce file size.

Can this tool validate JSON?

Yes. The tool automatically validates JSON as you type or paste. Invalid JSON shows a red error message with the line and position of the syntax error.

Does it support JSON with comments?

Standard JSON does not support comments. If your JSON contains // or /* */ comments (JSONC format), they will cause a validation error. Remove comments before formatting.

JSON Formatter & Viewer

Format, validate, minify, and explore JSON data. 100% client-side — your data never leaves your browser.

Input Auto-format on paste

Output

Indent:

How to Format JSON

Paste

Paste your JSON into the input panel. The tool auto-detects and validates it instantly.

Format

Click Format to beautify, or Minify to compress. Choose 2-space, 4-space, or tab indentation.

Copy

Copy the result to clipboard or switch to Tree View to explore nested structures visually.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is the dominant format for APIs, configuration files, and data storage across the web.

JSON supports six data types: strings (text in double quotes), numbers (integers and decimals), booleans (true/false), null, arrays (ordered lists), and objects (key-value pairs). Every valid JSON document is either an object {} or an array [] at the top level.

Features

Format & Beautify

Transform minified JSON into properly indented, human-readable format. Choose between 2-space, 4-space, or tab indentation to match your project style.

Minify

Remove all whitespace and line breaks to produce the smallest possible JSON output. Ideal for production APIs, config files, and reducing payload size.

Validate

Instant JSON validation with clear error messages pointing to the exact line and character position of syntax errors. Catches missing commas, unquoted keys, trailing commas, and more.

Tree View

Explore JSON as a collapsible tree structure. Click to expand/collapse objects and arrays. See data types color-coded: strings in green, numbers in yellow, booleans in pink.

Common Use Cases

API debugging — format API responses to understand the data structure, find missing fields, and verify correct nesting.
Configuration files — validate and beautify package.json, tsconfig.json, .eslintrc, and other config files before committing.
Data analysis — explore large JSON datasets with tree view to understand structure without writing code.
Learning & teaching — visualize JSON structure for tutorials, documentation, and learning exercises.

Frequently Asked Questions

Is my JSON data safe?

Yes. All processing happens 100% in your browser using JavaScript. Your JSON data is never sent to any server. Nothing leaves your device. You can verify this by disconnecting from the internet — the tool works fully offline.

What is the maximum JSON size supported?

The tool handles JSON files up to 5–10 MB depending on your browser. For very large files, the text view is faster than tree view. If your browser becomes slow, try minifying first to reduce memory usage.

Can it fix invalid JSON?

The tool validates and highlights errors but does not auto-fix them. Common issues include trailing commas, single quotes instead of double quotes, unquoted keys, and missing brackets. The error message shows the exact position to help you fix it manually.

What is the difference between JSON and JSONC?

Standard JSON does not allow comments. JSONC (JSON with Comments) is an extension used by VS Code and TypeScript that allows // and /* */ comments. This tool validates standard JSON only — remove comments before formatting.

Is this JSON formatter free?

Yes. Completely free with no limits, no registration, and no ads. The tool runs entirely in your browser — it works even without an internet connection after the page loads.

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