Is there a way to pretty-print JSON in a web page using JavaScript?

Question

Seems to me that pretty-printing JSON is a simple enough task that JavaScript should be able to handle it. Has anyone ever written (or run across) a JavaScript function to do this?

Pliny

Answer 1

What I ended up doing is installing the JSONView add-on for Mozilla. Not perfect, but it gets done what I needed done.

Pliny

Answer 2

An easy way to do this is to execute:

JSON.stringify(data, null, "  ");

where data is the json object you want to print pretty.

Not every browser contains JSON though. You can include json.js by Douglas Crockford which add global JSON object if it is not supported natively by the browser.

Fleshly

JSON.stringify is not terribly pretty, even with extra spaces. I found the vkbeautify link below to be a great solution. – Rizas

this seems like a bad solution, since subsequent calls to pretty print JSON might be then bastardized – Keratosis

Answer 3

I use this bookmarklet code on my browsers to make the JSON paragraph readable

javascript:(function(){document.body.firstChild.innerHTML = JSON.stringify(JSON.parse(document.body.firstChild.innerHTML), null, 4);})();

Adding a bookmarklet is easy - right click on bookmarks bar - Add/New - provide a name and paste js in url / location box

As current day browsers are putting the json response in a <pre> tag inside, i use body.firstChild

Balustrade

This is awesome, still working in 2023 (if you ignore the word 'bookmarklet') ! – Agneta

Answer 4

take a look at vkbeautify.js plugin

http://www.eslinstructor.net/vkbeautify/

it provides pretty print for both JSON and XML text.

written in plain javascript, small and fast.

Puzzle

I really liked this solution. It worked great with node and I see they also have a browser version. – Rizas

Disclaimer: vkbeautify.json is a wrapper to JSON.stingify – Pacific

Answer 5

JavaScript data formatting/pretty printer

Dunedin

Answer 6

If you want this for yourself (debugging purposes) you can use Greasemonkey: http://misc.slowchop.com/misc/wiki/HumanReadableJSONGreasemonkey

If you want the output for your users: http://jsonformatter.curiousconcept.com/

Swollen

Answer 7

You can give this a try it will add in some nice CSS.

<pre style="font-family: Courier;background: #f4f4f4;border: solid 1px #e1e1e1;float: left;width: auto;">
    JSON.stringify(data, null,' ').replace('[', '').replace(']', '')
</pre>

Longoria