# JSON Formatter & Validator

Validate, format or compact JSON without rounding its number tokens.

[Open this tool](https://whatson.pk/developer-json-format-calculator/)

Category: Developer & Data

Readable JSON is easier to inspect than one long line, but formatting should not change its number tokens.

Paste a document and choose indentation or compact output. Review validation errors before copying the result.

## Inputs and controls

* JSON input
* Formatting: Pretty print; Compact
* Indent spaces: 2 spaces; 4 spaces
* Object keys: Keep entered order; Sort object keys

## How to use

* Paste or enter JSON input.

* Choose formatting, indent spaces and object keys.

* Select Process input. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.


## Why use this tool

Large integer spellings and empty structures stay intact during formatting.


## Before relying on the result

Duplicate object keys are rejected. Empty objects, empty arrays and numeric spelling are preserved. JSON depth is limited to 40.


## Tool limitations

Duplicate object keys are rejected. Empty objects, empty arrays and numeric spelling are preserved. JSON depth is limited to 40.

## Questions

### Are duplicate object keys accepted?

No. Duplicate keys are rejected so one value is not silently substituted for another.

### What should I check before using JSON Formatter & Validator?

Check JSON input, Formatting, Indent spaces and Object keys. Use the exact units shown beside the controls and replace any example values with your own inputs.

Source page last modified (UTC): 2026-10-04T16:58:29+00:00

This profile describes the tool. It does not execute it or supply a professional certification.