Last Updated: May 2026  ·  4 min read

Raw JSON from APIs, databases, and configuration files is often minified — all on one line, no spaces, no indentation. It's efficient for machines but impossible for humans to read. A JSON formatter takes that dense blob and turns it into clean, indented, readable code. If you work with APIs, config files, or data pipelines, this tool will save you hours.

What Is a JSON Formatter / Prettifier?

A JSON formatter (also called a JSON prettifier or JSON beautifier) adds consistent indentation and newlines to JSON data, making it readable. The inverse — minification — removes all whitespace to produce the smallest possible output.

You need a JSON formatter when:

  • Debugging an API response pasted from a network inspector
  • Reading a large config file (package.json, tsconfig.json, etc.)
  • Verifying the structure of a database export
  • Copying JSON from a minified bundle to understand it
  • Sharing JSON snippets with teammates

How to Use the JSON Formatter

Go to SolutionGigs JSON Formatter. It's free, runs entirely in your browser — no data is sent to any server.

  1. Paste your JSON into the input panel on the left
  2. Click Prettify — formatted output appears instantly on the right
  3. Adjust the indent size (2 or 4 spaces, or tabs)
  4. Click Copy Output to copy to clipboard

The formatter also includes:

  • Minify — compress JSON to a single line
  • Validate — check if JSON is syntactically valid
  • Fix JSON — attempt to repair broken JSON (unquoted keys, trailing commas, single quotes, comments)

JSON Formatter Keyboard Shortcuts

Action Shortcut
Format / Prettify Auto (600ms debounce)
Copy output Click "Copy Output"
Clear all Click "Clear"

Fix Broken JSON

The Fix JSON button repairs common issues:

  • Unquoted keys: {name: "Alice"} → {"name": "Alice"}
  • Trailing commas: [1, 2, 3,] → [1, 2, 3]
  • Single quotes: {'key': 'value'} → {"key": "value"}
  • JS comments: strips // comment and /* block */ comments
  • JS-only values: undefined → null, Infinity → null

This is especially useful for JSON exported from JavaScript code, config files with comments (like VS Code settings), or hand-written JSON with minor mistakes.

JSON Validation

The validator tells you exactly what's wrong with invalid JSON:

  • The character position of the syntax error
  • The line and column number
  • The error type (unexpected token, expected comma, etc.)

This is faster than reading a stack trace from your code.

Indent Size — Which Should I Use?

Indent Style
2 spaces JavaScript standard (prettier default)
4 spaces Python standard (json.dumps default)
Tab Some codebases, maximally compact horizontally

For most web projects, 2 spaces is the standard (matches ESLint/Prettier defaults).

JSON Formatting in Code

JavaScript:

const formatted = JSON.stringify(data, null, 2);  // 2-space indent
const minified  = JSON.stringify(data);

Python:

import json
formatted = json.dumps(data, indent=4)
minified  = json.dumps(data, separators=(',', ':'))

curl + jq (command line):

curl https://api.example.com/data | jq .

Frequently Asked Questions

Is my data sent to a server? No — the formatter runs entirely in your browser using JavaScript. Your JSON never leaves your device.

What's the maximum size JSON I can format? There's no enforced limit. In practice, very large JSON (10+ MB) may be slow in the browser. For large files, use jq on the command line.

Can it handle JSON with comments (JSONC)? Yes — use the Fix JSON button to strip comments and produce valid JSON.

What's the difference between JSON and JSONC? JSONC (JSON with Comments) is used by VS Code for config files. It's not valid JSON — the Fix JSON button converts it to valid JSON by removing comments.

Is there a JSON schema validator? Not in this tool. For schema validation, use AJV or JSON Schema Validator.

Mohammed Yaseen

Mohammed Yaseen

Founder, SolutionGigs

Mohammed has been building developer tools since 2018 and writes about JSON, JWT, regex, SQL, APIs, and web development utilities. LinkedIn →