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Pretty Print JSON - Format JSON Files Online

Turn minified JSON into readable, consistently indented formatting in your browser. Syntax errors surface immediately with clear messages.

Quick start

Built for format json with proper indentation and line breaks.

Everything runs in your browser, so you can test the workflow with sample data when available before using production files.

Output: A new file or report produced locally in your browser.

  1. 1Choose a supported file or use sample data when available.
  2. 2Set the options shown for this workflow.
  3. 3Process the file locally, inspect the result, and download a new copy.
Preparing your private workspace…

How to JSON Prettify

  1. 1Upload a .json file or minified API response.
  2. 2The tool parses and re-serializes with 2-space indentation.
  3. 3Invalid JSON stops immediately with the parser error shown.
  4. 4Download the formatted file or copy it into your editor.

Why Use This Tool?

  • ✓Readable Diffing - Formatted JSON works with git and code review
  • ✓Validation Included - Broken JSON is reported, not silently mangled
  • ✓Key Order Preserved - Object keys keep their original sequence
  • ✓Private - Sensitive payloads stay on your machine

Frequently Asked Questions

Will formatting change my data?

No. Whitespace is the only change — values, keys, and ordering are byte-identical apart from indentation.

How large can the file be?

Up to roughly 100MB within browser memory. Minified API dumps of a few MB format instantly.

Is this different from Minify JSON?

Yes — prettifying adds whitespace for readability, minifying strips every avoidable byte for transport.