Developer Tools

JSON Formatter

Format readable JSON without sending the document to a server.

Your data is processed locally in your browser and is never uploaded.Maximum: 4 MB per file. Input is not saved in browser storage or placed in the URL.
Output

How to use this tool

  1. Paste JSON or load a local file, choose indentation, then format it.
  2. Review the live result and use Copy result when you need to share it.

How the transformation works

JSON.parse checks syntax and JSON.stringify creates deterministic whitespace. Processing runs entirely in this browser. The page does not upload, persist, execute or remotely inspect the supplied content.

Processing rules

JSON.parse checks syntax and JSON.stringify creates deterministic whitespace. Processing runs entirely in this browser. The page does not upload, persist, execute or remotely inspect the supplied content.

Step-by-step transformation

  1. Paste JSON or load a local file, choose indentation, then format it.
  2. JSON.parse checks syntax and JSON.stringify creates deterministic whitespace. Processing runs entirely in this browser. The page does not upload, persist, execute or remotely inspect the supplied content.
  3. Check the displayed result, then copy it if needed.

Worked example

A nested services object is formatted while array order remains unchanged.

Methodology and review

Who this is for

Developers reviewing or presenting JSON locally.

Inputs and units

  • JSON text or local file
  • Indentation and optional key sorting

Method

The browser parses input with the native JSON grammar, optionally sorts object keys, and serialises it with the selected indentation.

Worked example

A minified nested object becomes consistently indented without changing its values.

Assumptions

  • Input is JSON rather than a JavaScript object literal.
  • Key order has no semantic meaning to the receiving system.

Common mistakes

  • Pasting JavaScript object syntax
  • Assuming formatting validates an API schema

Limitations

  • Formatting does not validate an external schema or preserve original whitespace.
  • Large integers may exceed JavaScript's exact numeric range.

How this tool was checked

Tests cover nested arrays and objects, escaping, sorting, malformed input, and the 4 MB limit.

Reference sources

Related tools

Calculation review: 21 August 2026. Published by Goldwave Dynamics Limited. This is an internal product review, not an independent certification.

Risk guidance

Frequently asked questions

Does this tool send my inputs anywhere?

No. The interactive calculation runs in your browser and this site does not submit tool inputs to a backend.

How should I use the result?

Check that the entered units and values match your situation, especially around dates, breaks, and rounding.

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