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108 byte CSS Layout Debugger

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

[].forEach.call($$("*"),function(a){a.style.outline="1px solid #"+(~~(Math.random()*(1<<24))).toString(16)})

Using document.querySelectorAll:

~ 131 byte version

[].forEach.call(document.querySelectorAll("*"),function(a){a.style.outline="1px solid #"+(~~(Math.random()*(1<<24))).toString(16)})

~73 byte code-golfed version by @xem

$$('*').map(A=>A.style.outline=`1px solid hsl(${(A+A).length*9},99%,50%`)

~66 byte code-golfed version by @daliborgogic

$$('*').map((A,B)=>A.style.outline=`1px solid hsl(${B*B},99%,50%`)

If you're looking for a proper version that uses a set color per tag type, check out pesticide.io.

Screenshots

Tested from Chrome DevTools:

Tested from Firefox DevTools:

Tested from WebKit Nightlies (Safari):

Tested in IE:

Thanks to gregwhitworth for verifying.

Tag Specific Layout Debugging In 82 Bytes

My original implementation outlined each DOM element on the page with a random (valid) hex color.

Thanks to the work by @aemkei, @p01, @sindresorhus and other commenters, we now have an even shorter version (108 bytes golfed down to 82) that uses a specific hex color per tag name. This lets you visually group elements similar to how pesticide.io does.

for(i=0;A=$$("*")[i++];)A.style.outline="solid hsl("+(A+A).length*9+",99%,50%)1px"

Preview:

Thanks for the awesome help improving this folks <3

function(a){ // Supply a valid selector (e.g '*' for wildcard)
[].forEach.call( // Treat Nodelist as an Array (fewer bytes than Array.prototype.forEach.call(...);)
// Gets the prototype of Array & uses call to execute the function on the NodeList.
document.querySelectorAll(a), // Query DOM for elements matching the supplied selector
// (For 108 bytes, use $$() as Chrome, Safari & FF expose it in DevTools)
function(b){
b.style.outline = "1px solid #" + // Set the selector outline
(~~(Math.random()*(1<<24))) // Pick a valid random CSS hex color
.toString(16)}) // Convert to a base 16 number. BOOM.
}
function(a){return [].forEach.call(document.querySelectorAll(a),function(b){b.style.outline = "1px solid #" +(~~(Math.random()*(1<<24))).toString(16)});}
{
"name": "CSSLayoutDebugger",
"description": "A helper for debugging CSS layouts",
"keywords": [
"css",
"layout",
"debugger"
]
}
<!DOCTYPE html>
<title>CSS Layout Debugger</title>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<div>I am element</div>
<script>
var myFunction = function(a){ // Supply a valid selector (e.g '*' for wildcard)
[].forEach.call( // Treat Nodelist as an Array (fewer bytes than Array.prototype.forEach.call(...);)
// Gets the prototype of Array & uses call to execute the function on the NodeList.
document.querySelectorAll(a), // Query DOM for elements matching the supplied selector
// (For 110 bytes, use $$() as Chrome, Safari & FF expose it in DevTools)
function(b){
b.style.outline = "1px solid #" + // Set the selector outline
(~~(Math.random()*(1<<24))) // Pick a valid random CSS hex color
.toString(16)}) // Convert to a base 16 number. BOOM.
}
myFunction('*');
</script>
<!-- quick JSBin:http://jsbin.com/soseq/2/edit -->
@heldr
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heldr commented Sep 30, 2014

I wrote a togglable bookmarklet based on the results already reached

javascript:!function(a){for(a.__CSSDebug__=!a.__CSSDebug__,i=0;A=document.all[i++];)A.style.outline=a.__CSSDebug__?"solid hsl("+9*(A+A).length+",99%,50%)1px":null}(window);

@addyosmani
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Author

addyosmani commented Oct 7, 2014

This version should play better with Polymer and Custom Elements (94 bytes):

for(i=0;A=$$("html /deep/ *")[i++];)A.style.outline="solid hsl("+(A+A).length*9+",99%,50%)1px"

@JotFX
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JotFX commented Oct 10, 2014

Hi guys, some hours ago I twittered another version, but that relied on the 108 byte version. I tinkered with the golfed down version above and now its 79 bytes and should still work fine:

for(i=0;A=$$("*")[i++];)A.style.outline="1px solid #"+(i*999%4096).toString(16)

The coloring should be as distinguishable as the random version. Not sure if the first element gets a valid color coding.

@markyun
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markyun commented Oct 11, 2014

mark

@amirouche
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amirouche commented Feb 8, 2015

modified the "every element gets a color" to use hsl:

[].forEach.call(
    document.querySelectorAll("*"),
    function(a){
        a.style.outline="1px solid hsl(" + Math.random() * 360 +", 70%, 70%)";
    }
)

@shmdhussain
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shmdhussain commented Feb 7, 2016

Once I enabled the outlines, how could I undo it? Thanks For any help in advance.

@jbmartinez
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jbmartinez commented Feb 8, 2016

@shmdhussain reload/refresh the page

@addyosmani
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Author

addyosmani commented Sep 26, 2016

Reloading the page will remove the outlines :)

@lukechilds
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lukechilds commented Sep 26, 2016

81 bytes if es2015 is allowed.

for(i=0;A=$$("*")[i++];)A.style.outline=`solid hsl(${(A+A).length*9},99%,50%)1px`

@lukechilds
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lukechilds commented Sep 26, 2016

Actually, make that 77.

$$("*").forEach(A=>A.style.outline=`solid hsl(${(A+A).length*9},99%,50%)1px`)

@addyosmani
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Author

addyosmani commented Sep 26, 2016

Nice golfing, @lukechilds. On first try, seems to be working well with the latest ES2015 version:

screen shot 2016-09-26 at 3 41 12 pm

Need to do a little work comparing effectiveness of the randomisation approaches on-thread, but imagine that won't matter hugely to some folks.

@lukechilds
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lukechilds commented Sep 26, 2016

@addyosmani 74 bytes. We're almost at half a tweet.

for(A of $$('*'))A.style.outline=`solid hsl(${(A+A).length*9},99%,50%)1px`

Ok, I think I'm done.

@zak905
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zak905 commented Sep 27, 2016

Cool! this should be integrated into chrome

@JyotiDuhan
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JyotiDuhan commented Sep 28, 2016

Hi,
Can anyone tell me what is the purpose of using this? I loved to see my page layout in multiple color blocks though :)

@xem
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xem commented Oct 12, 2016

73b, did I win?

$$('*').map(A=>A.style.outline=`1px solid hsl(${(A+A).length*9},99%,50%`)

@shockw4ver
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shockw4ver commented Nov 29, 2016

It's likely to build a simple plugin integrated into browser and make it easy to clear a page.
Excellent!

@daliborgogic
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daliborgogic commented Jul 29, 2017

# ~66 bytes
$$('*').map((A,B)=>A.style.outline=`1px solid hsl(${B*B},99%,50%`)
# ~64 bytes but not so colorful
$$('*').map((A,B)=>A.style.outline=`1px solid hsl(${B},99%,50%`)

rainbow

@streamich
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streamich commented Sep 8, 2017

57 bytes:

[...document.all].map(a=>a.style.outline="1px solid red")

@nitinja
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nitinja commented Oct 27, 2017

I think we should try to minimize the number of outlines. More dom elements present on the page, slower it gets.

@addyosmani
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Author

addyosmani commented Oct 31, 2017

@daliborgogic Nice work further code-golfing! Looks pretty alight :)

image

@daliborgogic
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daliborgogic commented Dec 21, 2017

@addyosmani Thank you : )

@daliborgogic
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daliborgogic commented Dec 21, 2017

@nitinja I agree, but this is not for production.

@boi23
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boi23 commented Aug 20, 2018

Im havin trouble with my css can u help me

@adriadrop
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adriadrop commented Jan 11, 2019

I made a module for drupal inspired by this code https://www.drupal.org/project/css_debuger
I added option to show/hide boxes with alt+c

@shinsenter
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shinsenter commented Mar 1, 2019

Very useful. String interpolation does not work on IE.

@shinsenter
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shinsenter commented Mar 1, 2019

Here is bookmarklet version:

javascript:[].slice.call(document.querySelectorAll("*")).map(function(l,e){l.style.outline="1px solid hsl("+(e*e)+",90%,50%)"})

@noobalex
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noobalex commented Jan 13, 2020

Perhaps you need a bookmark to restore the layout

javascript:[].slice.call(document.querySelectorAll("*")).map(function(l,e){l.style.outline="none"})

@y4rr
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y4rr commented Dec 27, 2020

Perhaps you'd like to have just one bookmarklet instead of two. And nicer colors.

Properly escaped code for the bookmarklet:

javascript:(function()%7B%5B%5D.slice.call(document.querySelectorAll(%22*%22)).map(function(l%2Ce)%7Bl._CSSDEBUG%3D!l._CSSDEBUG%3Bl.style.outline%3Dl._CSSDEBUG%3F%22solid%20hsl(%22%2B(l%2Bl).length*13%2B%22%2C45%25%2C55%25)0.1rem%22%3A%22initial%22%7D)%7D)()

Source:

javascript:[].slice.call(document.querySelectorAll("*")).map(function(l,e){l._CSSDEBUG=!l._CSSDEBUG;l.style.outline=l._CSSDEBUG?"solid hsl("+(l+l).length*13+",45%,55%)0.1rem":"initial"})

@dziku86
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dziku86 commented Feb 21, 2021

1 byte can be shaved with Q unit if you are not using Safari/IE:

$$('*').map((A,B)=>A.style.outline=`1q solid hsl(${B*B},99%,50%`)

@amir2mi
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amir2mi commented May 18, 2021

57 bytes:
[...document.all].map(a=>a.style.outline="1px solid red")

Hi, @streamich thanks! it is possible with CSS, the random color is the point.

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