JSON Formatter
FreeFormat, validate, and minify JSON with syntax highlighting and error detection
jsonformatvalidateminifyprettify
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How it works
1
Paste
Paste or type your raw JSON into the editor on the left.
2
Format
Click Format to pretty-print with indentation, or Minify to compress into a single line.
3
Copy
Copy the formatted output or review inline validation errors highlighted in the editor.
Frequently asked questions
Is my JSON data sent to a server?+
No. All formatting, validation, and minification runs in your browser. Your data never leaves your device, so you can safely paste API keys, config files, or any sensitive JSON.
What counts as valid JSON?+
Valid JSON follows the ECMA-404 standard: objects use double-quoted keys, strings use double quotes, no trailing commas, and no comments. The formatter highlights exactly where your JSON breaks these rules.
Can I format large JSON files?+
Yes. The formatter handles files up to several megabytes directly in the browser. For extremely large files, performance depends on your device's available memory.
What is the difference between format and minify?+
Format adds indentation and line breaks so humans can read the structure. Minify strips all unnecessary whitespace to produce the smallest possible output, which is ideal for APIs and storage.
Does the formatter fix invalid JSON automatically?+
No. It validates and shows you exactly where errors are so you can fix them yourself. Auto-fixing could silently change your data's meaning, so the tool only highlights problems.