JSON Formatter & Validator
Format, validate, and minify JSON data online for free. Pretty-print with customizable indentation or compact into a single line. Upload a .json file or paste JSON directly. Runs entirely in your browser.
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About This Tool
How to Use
- 1Upload a .json or .txt file (up to 5 MB) by clicking the upload area or dragging and dropping.
- 2Select "Pretty Print" to format the JSON with indentation, or "Minify" to compact it.
- 3If pretty-printing, choose your preferred indent size: 2 spaces, 4 spaces, or tab.
- 4Click "Process" to format or minify the JSON.
- 5Download the output file or copy it from the preview panel.
When to Use
- •When debugging API responses that come as a single long line of JSON.
- •When preparing readable JSON configuration files for a codebase.
- •When minifying JSON payloads to reduce file size for production.
- •When validating that a JSON file is syntactically correct before using it.
- •When sharing formatted JSON with teammates for code reviews.
Tips & Tricks
- ✨Use 2-space indentation for compact yet readable JSON files.
- ✨Minified JSON is ideal for API payloads and configuration files where size matters.
- ✨If you get a validation error, check for trailing commas or unquoted keys which are common mistakes.
- ✨Large JSON files (over 1 MB) may take a moment to process in the browser.
Frequently Asked Questions
JSON formatting (also called pretty-printing) adds whitespace, line breaks, and indentation to make JSON data human-readable. Minifying does the opposite, removing all unnecessary whitespace to create the smallest possible file.
Yes. The tool parses your JSON using the browser native JSON.parse function. If the JSON is invalid, you will see a detailed error message indicating what went wrong and where.
Absolutely. All processing happens entirely in your browser. Your JSON data is never uploaded to any server, stored, or logged anywhere.
The tool accepts files up to 5 MB. For very large files, processing may take a moment depending on your device performance.
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