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Utilnivo

Developer

Utilnivo

JSON Formatter & Beautifier

Format and beautify JSON with indentation—free online developer tool.

No registration
  • On your device

Browse more in Developer or all tools.

Why is my JSON invalid?

Common causes: trailing commas after the last property, single-quoted strings instead of double quotes, unescaped line breaks inside strings, and comments (JSON does not allow // or /* */). The formatter highlights the parse error line when the browser reports a position—fix that token first, then re-validate.

Private on your device

Your information stays on your device and is not uploaded.

Related tools

This JSON formatter beautifier combines validation, indentation, and copy-ready output in one page. Paste minified JSON from logs or APIs, beautify for review, and switch to minify when you need compact wire format.

Formatter and beautifier are the same operation—adding readable indentation to valid JSON.

Pair with JSON compare when reviewing two API versions side by side.

How to use this tool

Paste JSON, run beautify or format, review errors if any, then copy or toggle minify for compact output.

Worked example

Example: beautify a minified GraphQL error response to read the errors array, then minify again for a compact Slack attachment.

When to use this

  • Support triage on customer JSON payloads.
  • Cleaning samples before publishing documentation.
  • Teaching JSON structure in workshops or onboarding.

Common examples

  • Minified API response from `curl` → indented JSON for diffing against staging.
  • Invalid trailing comma in config JSON → parser error line highlighted before deploy.
  • Large nested object → collapse sections mentally after pretty-print for code review.
  • Stripe webhook payload → pretty-print to inspect nested `data.object` fields.
  • package-lock fragment → validate structure before pasting into a bug report.

Common mistakes

  • Beautifying invalid JSON and blaming the tool for parse errors.
  • Sharing beautified output containing live tokens or PII.
  • Leaving BOM characters from some editor exports.

How it works

Paste JSON to format it with readable indentation or minify it into a single line. Invalid JSON shows a parse error with line and column when available. Optional key sorting orders object keys alphabetically. Formatting works on your device.

Limitations

Invalid JSON will not format until syntax errors are fixed. Very large documents may slow the browser tab.

Privacy and file handling

Your data stays on your device and is not uploaded.

Related JSON Formatter pages

These pages use the same json formatter with examples tailored to different tasks.

FAQ

Frequently asked questions

Is formatter the same as beautifier?

Yes. Both add indentation and line breaks to make JSON human-readable.

Can I minify after beautifying?

Yes. Use the minify control to remove whitespace again without changing data.

Does beautify fix syntax errors?

No. Only valid JSON can be beautified—fix syntax issues first.

Related pages

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