Z

JSON Formatter & Validator

Format, validate, and minify JSON instantly. Runs entirely in your browser — your data never leaves your device.

Input

⌘↵ format · Esc exit fullscreen

How to use

  1. 1 Paste your JSON into the input panel on the left.
  2. 2 Pick indent size (2, 4, or tab) and toggle Sort keys if needed.
  3. 3 View the formatted, minified, or tree output on the right. Copy or download with one click.

Why use this tool

  • Runs entirely in your browser — your JSON never leaves your device.
  • Real-time syntax validation with line and column error reporting.
  • Switch between pretty, minified, and collapsible tree views.
  • Resizable split-pane, fullscreen mode, and live stats for large payloads.
  • Free, no signup, no ads, no rate limits.

Frequently asked questions

Is this JSON formatter really free?

Yes — completely free. No signup, no ads, no rate limits. The formatter runs in your browser so your data never reaches our servers.

How large a JSON file can it handle?

Up to ~10 MB efficiently. For very large payloads, paste in chunks or use a streaming parser.

Does it validate JSON syntax?

Yes — real-time validation. When parsing fails, the error includes a line and column so you can jump straight to the problem.

Can I sort object keys alphabetically?

Yes. Toggle "Sort keys" in the settings bar. The sort is recursive — nested objects are sorted too.

What about minification?

Switch the output to Minified to strip all whitespace. Useful for reducing payload size before transport.

Can I resize the input and output panels?

Yes — drag the divider between the panels on desktop. Double-click the divider to reset to a 50/50 split. Each panel also has a fullscreen toggle.

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