How to disable CSS in Browser for testing purposes

134
votes

Is there any way I can disable all external CSS in a browser (Firefox, Chrome...)?

When using slower internet connection, sometimes only the bare HTML is loaded by the browser without the CSS info. It looks like the page has been laid raw on the screen. You would have noticed this with StackOverflow too.

I want to make sure that my web page shows up OK even if the CSS files are not loaded.

I didn't mean I want to convert external CSS to inline. But I want a way to explicitly disable all CSS from the browser so that I can reposition my elements in a better, readable way.

I know I can remove the <link rel='stylesheet'> entries, but what if I have a lot of linked pages?

17
htmlcssbrowser
This is a very good question. As it appears, for example, Chrome does not allow to "turn off" the author style sheets in a way that is acceptable for a standard user. This makes Chrome not conform to CSS 2.1, as can be seen in Chapter 3.2.6 of the spec, where it is said, that "The UA must allow the user to turn off the influence of author style sheets." The same could be true for other browsers that do not allow it natively. – NicBright
right-click the page, select Inspect from the context menu, locate the <head> tag, right-click, and pick Delete element. – ccpizza

17 Answers

65
votes

The Web Developer plugin for Firefox and Chrome is able to do this

Once you have installed the plugin the option is available in the CSS menu. For example, CSS > Disable Styles > Disable All Styles

Alternatively with the developer toolbar enabled you can press Alt+Shift+A.

78
votes

In Chrome/Chromium you can do this in the developer console.

  1. Bring up the developer console by either ctrl-shift-j or Menu->Tools->Developer Console.
  2. Within the developer console browse to the Sources tab.
  3. In the top-left corner of this tab is an icon with a disclosure triangle. Click on it.
  4. Browse to <domain>→css→<css file you want to eliminate>
  5. Highlight all of the text and hit delete.
  6. Rinse and repeat for each stylesheet you want to disable.
23
votes

Firefox (Win and Mac)

  • Via the menu toolbar, choose: "View" > "Page Style" > "No Style"
  • Via the Web Developer Toolbar, choose: "CSS" > "Disable Styles" > "All Styles"

If the Web Dev Toolbar is installed, people can use this keyboard shortcuts: Command + Shift + S (Mac) and Control + Shift + S (Win)

  • Safari (Mac): Via the menu toolbar, choose "Develop" > "Disable Styles"
  • Opera (Win): Via the menu, choose "Page" > "Style" > "User Mode"
  • Chrome (Win): Via the gear icon, choose the "CSS" tab > "Disable All Styles"
  • Internet Explorer 8: Via the menu toolbar, choose "View" > "Style" > "No Style"
  • Internet Explorer 7: via the IE Developer Toolbar menu: Disable > All CSS
  • Internet Explorer 6: Via the Web Accessibility Toolbar, choose "CSS" > "Disable CSS"
18
votes

This script works for me (hat tip to scrappedcola)

var el=document.getElementsByTagName('*');for(var i=0;i<el.length; i++){if (el[i].getAttribute("type")=="text/css") el[i].parentNode.removeChild(el[i]); };

inline style stays intact, though

11
votes

Expanding on scrappedocola/renergy's idea, you can turn the JavaScript into a bookmarklet that executes against the javascript: uri so the code can be re-used easily across multiple pages without having to open up the dev tools or keep anything on your clipboard.

Just run the following snippet and drag the link to your bookmarks/favorites bar:

<a href="javascript: var el = document.querySelectorAll('style,link');
         for (var i=0; i<el.length; i++) {
           el[i].parentNode.removeChild(el[i]); 
         };">
  Remove Styles 
</a>
  • I would avoid looping through the thousands of elements on a page with getElementsByTagName('*') and have to check and act on each individually.
  • I would avoid relying on jQuery existing on the page with $('style,link[rel="stylesheet"]').remove() when the extra javascript is not overwhelmingly cumbersome.
11
votes

Install Adblock Plus, then add *.css rule in Filters options (custom filters tab). The method affect only on external stylesheets. It doesn't turn off inline styles.

Disable all external CSS

This method does exactly what you asked.

6
votes

Delete <head> with a bookmarklet

For pages that rely on external CSS (most pages nowadays) you can delete the head element:

document.querySelector("head").remove();

Usage: right-click the page (in Chrome/Firefox), select Inspect, paste the code above in the devtools console and press Enter.

A bookmarklet version of the same code that you can paste as the URL of a bookmark:

javascript:(function(){document.querySelector("head").remove();})()

Now clicking the bookmark on in your Bookmarks bar will (hopefully) strip all the css stylesheets.

Delete <head> via devtools

Another way to achieve it is to right-click the page (in Chrome/Firefox), select Inspect, in devtools panel, Elements tab select the <head> tag (see screenshot), right-click it, and pick Delete element:

delete the head tag

Removing the head will not work for pages that use inline styles.

Safari-only solution

If you happen to use Safari on MacOS then:

  1. Open Safari Preferences (cmd+,) and in the Advanced tab enable the checkbox "Show Develop menu in menu bar".
  2. Now under the Develop menu you will find a Disable Styles option.
4
votes

Another way to achieve @David Baucum's solution in fewer steps:

  1. Right click -> inspect element
  2. Click on the stylesheet's name that affect your element (just on the right side of the declaration)
  3. Highlight all of the text and hit delete.

It could be handier in some cases.

4
votes

As most answers seem to be pretty old here, referencing menu items I can't seem to find in the current versions of popular browsers, here's how to do it in the current version in Firefox Developer Edition:

  • Open Developer Tools (CTRL + SHIFT + I)
  • Select the Style Editor tab
  • There you should see all sources of CSS in your document. You can disable each of them by clicking the eye icon next to them.

White eye icon = enabled; Gray eye icon = disabled

2
votes

I tried in Chrome Developer tools and the method is valid only if the CSS are included as external files and it won't work for inline styles.

Array.prototype.forEach.call(document.querySelectorAll('link'), (element)=>element.remove());

Or

var linkElements = document.querySelectorAll('link');
Array.prototype.forEach.call(linkElements, (element)=>element.remove());

Explanations

  1. document.querySelectorAll('link') gets all the link nodes. This will return array of DOM elements. Note that this is not Array object of javascript.
  2. Array.prototype.forEach.call(linkElements loops through the link elements
  3. element.remove() removes the element from the DOM

Resulting in plain HTML page

2
votes

you can block any request (even for a single css file) from inspector with the following:
    Right click > block request URL
without disabling other css files > https://umaar.com/dev-tips/68-block-requests/ It's a standard inspector feature, no plugins or tricks needed

1
votes

On Firefox, the simplest way is via the menu command View > Page Style > No Style. But this also switches off the effects of some presentational HTML markup. So using plugins as suggested by @JoelKuiper is usually better; they give more flexibility (e.g., switching off just some style sheets).

0
votes

Actually, it's easier than you think. In any browsers press F12 to bring up the debug console. This works for IE, Firefox, and Chrome. Not sure about Opera. Then comment out the CSS in the element windows. That's it.

0
votes

While inspecting HTML with the Browser Development tool you prefer (eg Chrome Devtools) find the <head> element and delete it at all.

Notice that this will also remove js but for me it is the fastest way to get the page naked.

0
votes

All the suggested answers merely eliminate the css for that page load. Depending on your use-case, you may wish to not load the css at all:

Chrome Dev Tools > Network Tab > Right click on stylesheet in question > block request url

0
votes

For those who don't want any plugin or other stuffs, We can use the document.styleSheets to disable/enable the css.

// code to disable all the css

for (const item in document.styleSheets) {
  document.styleSheets[item].disabled=true;
}

If you use chrome, you can create a function and add to your snippets. So that you can use the console to enable/disable the css for any sites.

// Snippets -> DisableCSS

function disableCss(value = true){
  for (const item in document.styleSheets) {
    document.styleSheets[item].disabled=value;
  }  
}

// in console

disableCss() // by default is disable
disableCss(false) // to enable
-1
votes

For Chrome:

  1. Open Dev Tools (inspect element).
  2. Go to "network" tab.
  3. Select any css file and right-click: "Block request url".
  4. Go to the inspector´s footer to a "networking request blocking" tab.
  5. Click on plus icon, and add some pattern like "*.css".
  6. Reload the webpage.

This process allow to disable all css files at once.