AwesomeDevKit
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Free developer utility

JSON Formatter & Validator

Format, validate, minify, and inspect JSON data instantly — all processing happens in your browser. No data sent to any server.

Input: 150 chars
OutputValid JSON
{
  "name": "AwesomeDevKit",
  "version": "1.0.0",
  "tools": ["regex tester", "cron gen", "json fmt"],
  "nested": { "enabled": true, "count": 42 }
}

Why Use This JSON Formatter?

Most online JSON formatters send your data to a server. This one runs entirely in your browser using native JavaScript — your API responses, config files, and sensitive payloads stay private. Format with 2-space or 4-space indentation. Validate instantly. Minify for production.

Features

  • Format & beautify: 2-space or 4-space indentation with syntax highlighting.
  • Validate: Instant error detection with line-level messages for missing quotes, trailing commas, and unclosed brackets.
  • Minify: Compress JSON to a single line to reduce payload size.
  • Key/value summary: Count keys, values, and detect the root type at a glance.
  • Privacy-first: All processing is client-side. Your data never leaves your browser.

Common JSON Errors

Trailing commas

JSON forbids commas after the last array item or object property.

Single quotes

JSON requires double quotes for all strings and keys. Replace all single quotes.

Unquoted keys

All object keys must be double-quoted. No exceptions.

Comments

JSON does not support comments (// or /* */). Remove them or use JSONC.

Related Tools

Diff Checker

Compare two JSON payloads side by side.

Base64 Encoder

Encode or decode Base64-encoded JSON payloads.