JSON Formatter
Format, compress and validate JSON data online
💡 Click output to auto-copy · All data is processed locally in your browser
About This Tool
A JSON formatter is an essential tool for every developer working with APIs, configuration files, and data exchange. This free online JSON formatter lets you beautify, compress, and validate JSON data instantly — all in your browser.
Common use cases include debugging API responses during development, formatting configuration files like package.json or tsconfig.json, validating JSON before importing it into a database, and sharing formatted JSON snippets with your team. Whether you're preparing a bug report that includes API output or just need to read a messy JSON blob, this tool makes it clean and readable.
The JSON formatter supports adjustable indentation (2 spaces, 4 spaces, 1 space, or minified), real-time error detection with descriptive messages, and one-click copy of the output.
How to Use
- Paste your JSON into the left editor, or type it directly.
- Pick an indent size: 2 or 4 spaces for readability, Minified for production payloads.
- Click Format to beautify, Compress to strip all whitespace, or Validate to check syntax only.
- Click the output area to copy the result straight to your clipboard.
Tip: Validate is the fastest way to check a config file before committing it.
Common Mistakes
1. Single quotes instead of double quotes
JSON requires double quotes around keys and string values. Pasting JavaScript source with single quotes fails to parse — convert the quotes first.
2. Trailing commas
A comma after the last property breaks every strict JSON parser, even though JavaScript objects tolerate it. Watch for it when editing files by hand.
3. Unquoted keys
Syntax like an unquoted key name is valid JavaScript object notation but invalid JSON. Every key must be a wrapped string.
4. Comments in JSON
JSON has no comment syntax. If a config file contains comment lines, strip them before validating or feeding the file to any parser.