Curious Concept


The JSON Formatter was created to help with debugging. As data expressed as JSON is often written without line breaks to save space, it became extremely difficult to actually read and make sense of it. This tool hopes to solve the problem by formatting and validating JSON data so that it is easy to read and debug by human beings.

This third major iteration of the JSON Formatter & Validator has been immensely improved by users suggestions. Thanks everyone. If you have any other requests, be sure to .

JSON Formatter & Validator


Learn About JSON

To learn more about JSON check out some of the links below.


Following the description of JSON set out by Douglas Crockford of in RFC 4627, a validation scheme has been implemented. While JSONP is now accepted, only the JSON within is actually validated. This is due to the fact that there is not yet a conclusive standard for JSONP to validate against.

If you experience any problems, please sound the alarm.


Once added to your bookmarks toolbar, this bookmarklet will allow you to quickly and easily submit JSON URLs to be formatted and validated! When you are on a URL that is JSON Data, simply click the bookmarklet and it will immediatly open a new window that submits the link to this site for formatting and validation.

To install drag this link: Format & Validate JSON into your bookmarks toolbar.


Added due to public demand. Any and all donations are greatly appreciated.


April 2013

March 2013

February 2013

Fixed a number validation bug. Thanks to Chris and Anonymous for reporting it.

January 2013

May 2011

February 2011

November 2009

Changed to Hawk Host, service should be much faster now.

December 2008

Added a Select All button as requested and fixed url validation and output bugs.

November 2008

Released a completely rewritten version of the JSON Formatter. Many improvements and new features such as multiple results, templates, more robust parser, improved error messages, validation, and resizable textareas. Thanks to everyone for their suggestions!

A Long Time Ago... in 2007

Initial release of the JSON Formatter.


The backend is built with PHP using CodeIgniter, the frontend was built to HTML5/CSS3 standards with assistance from Iconic, jQuery and jQueryUI.

The JSON Formatter & Validator is periodically tested new versions of Firefox, Chrome, Opera & IE.