JSON Formatter & Validator

Format, validate, and minify JSON data. Free, instant, no signup.

ADSENSE_SLOT_TOP

📝 JSON Input 0 lines · 0 chars

Formatted Output
ADSENSE_SLOT_MIDDLE

🌲 Tree View

Explore parsed JSON in a collapsible tree structure. Click arrow icons to expand/collapse objects and arrays.

Paste valid JSON in the editor above to see the tree view.

How to Use This JSON Formatter

  1. Paste your JSON — Copy any JSON data and paste it into the input box above. It can be minified, messy, deeply nested, or have mixed indentation styles.
  2. Choose an action — Click Format to beautify with consistent indentation (2 or 4 spaces, or tabs), or Minify to compress it to a single line for production use.
  3. Check for errors — If your JSON has syntax issues, an error message appears with the approximate line and position. Fix the error and the output updates automatically.
  4. Copy or download — Click Copy to copy the result to your clipboard, or Download to save it as a .json file.

Tip: You can also use Ctrl + Enter to format, or right-click in the editor to paste and auto-format.

Why Use This JSON Formatter?

Instant, local processing

All formatting runs in your browser with JavaScript. No waiting on server round-trips — results appear in under 50ms, even for large JSON files.

Complete privacy

Your JSON data never leaves your device. No uploads, no server logs, no tracking. Safe for API keys, database exports, configuration files, and proprietary data.

Helpful error messages

Beyond basic JSON.parse errors, the validator detects common mistakes: trailing commas, unquoted keys, single-quoted strings, and mismatched brackets — with line-level pointers.

Tree view explorer

Large nested JSON structures are hard to read linearly. The collapsible tree view lets you drill down into specific paths and expand only what you need.

Size comparison

After formatting or minifying, see the character count change — useful for checking how much bandwidth you save by minifying API responses.

Frequently Asked Questions

What is JSON formatting / beautifying?

JSON formatting (also called beautifying or pretty-printing) adds consistent indentation and line breaks to JSON data, making it easy to read and debug. It does not change the actual data — only the whitespace. Minified JSON like {"a":1,"b":2} becomes multi-line with proper indentation.

When should I format vs. minify JSON?

Format when you are reading, debugging, or editing JSON by hand. Minify when you are deploying to production — minified JSON is smaller (sometimes 40-60% smaller), which reduces bandwidth and improves page load speed. Most APIs return minified JSON for this reason.

Can this handle very large JSON files?

Yes, within browser memory limits. Files up to ~10 MB format near-instantly. For files larger than 50 MB, you may experience a brief delay. The tool runs entirely in your browser, so performance depends on your device.

What common JSON errors does the validator catch?

Trailing commas (the most common mistake), unquoted object keys, single quotes instead of double quotes, missing commas between items, and mismatched brackets/braces. Each error shows an approximate line number to help you find and fix it.

Is this tool free to use?

Yes, completely free. No signup, no download, no limits. We support the tool with ads, but you can format as much JSON as you need.

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