JSON Validator & Formatter

Validate, format and repair JSON up to 50 MB. Everything runs in your browser — nothing is uploaded.

Attempt to repair invalid JSON

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Features

Smart Formatting

Automatically formats and indents your JSON with proper structure

Error Recovery

Attempts to repair common JSON errors and format partially valid data

Syntax Highlighting

Beautiful syntax highlighting with line numbers for easy reading

Pro Tips

• Use the checkbox to toggle JSON repair functionality
• The validator can fix missing quotes, trailing commas, and unmatched brackets
• Look up any parse error to see what it means and how to fix it
• Validating replaces your text with the formatted result. To keep the original and choose the indentation, use the beautifier

JSON Data Types

"string"Text values

123Numbers

true/falseBooleans

nullNull value

[...]Arrays

{...}Objects

No cookies, no accounts, no tracking. Your JSON and text are processed entirely in your browser and never sent anywhere. We count anonymous page views (the page address only, nothing about you or your device), and use localStorage to remember your theme.

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