JSON · Formatter

JSON Formatter & Beautifier

Format, beautify, and pretty print JSON online with customizable indentation, key sorting, and instant syntax validation. 100% private in-browser tool.

Interactive Editor

Indent:

Sort keys

Input JSON

Ln 1, Col 1·0 lines · 0 B

Auto-executes on edit

Formatted JSON Output

0 lines · 0 B

100% In-Browser Privacy: All conversions, formatting, and validations run purely on your machine using client-side JavaScript. Your data, code snippets, and environment variables are never transmitted to any server or recorded in logs.

Specifications

How JSON Formatter Works

Parses raw or minified JSON strings into abstract JavaScript data structures.
Re-serializes data with customizable 2-space, 4-space, or tab indentation for maximum human readability.
Offers recursive alphabetical key sorting to enable clean visual and structural diffing.
Highlights malformed JSON errors with exact line and column coordinates.

Demonstration

Example Input & Output

The formatter parses compact JSON text, validates RFC 8259 compliance, indents nested objects and arrays with clean 2-space or 4-space formatting, and optionally sorts object keys alphabetically.

Input JSON

{"name":"Sandeep","role":"Developer","skills":["TypeScript","Astro","Tailwind"],"settings":{"active":true,"theme":"dark"}}

Formatted JSON Output

{
  "name": "Sandeep",
  "role": "Developer",
  "settings": {
    "active": true,
    "theme": "dark"
  },
  "skills": [
    "TypeScript",
    "Astro",
    "Tailwind"
  ]
}

Applications

Common Use Cases

API Response Debugging

Inspect compacted JSON payloads from REST APIs, GraphQL endpoints, or microservices in clean human-readable structure.

Log Inspection

Format dense, single-line JSON log entries from CloudWatch, Datadog, or Elasticsearch into readable objects.

Database Records Inspection

Beautify raw document dumps from MongoDB or PostgreSQL JSONB columns.

Guidelines

Key Specifications & Gotchas

Trailing Commas

Standard JSON (RFC 8259) strictly forbids trailing commas after the last array item or object property.

Single Quotes

Keys and string values must use double quotes ("key": "value"), not single quotes.

Unquoted Keys

JavaScript object literal syntax ({key: 123}) is invalid in standard JSON.

Questions

Frequently Asked Questions

How do I format JSON online?

Paste your unformatted or minified JSON into the editor, select your preferred indentation (2 spaces, 4 spaces, or tabs), and the beautified output appears instantly.

What is JSON beautification?

JSON beautification (or pretty printing) transforms compact, single-line JSON text into an indented hierarchical structure with consistent newlines for effortless human readability.

How do I pretty print JSON?

Paste your payload into the input pane; the formatter automatically applies standard indentation and highlights syntax in real time.

Can I format invalid or malformed JSON?

No, the formatter requires valid JSON grammar. If your input has syntax errors, line-by-line diagnostics will pinpoint the exact token to fix.

Is my JSON sent to an external server?

No. 100% of formatting, sorting, and linting occurs directly inside your web browser using client-side JavaScript.

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