Eliminate flash of unstyled content

user_243460 0
Viewed 59524

How do I stop the flash of unstyled content (FOUC) on a web page?

fouc css
13 Answers

The problem with using a css style to initially hide some page elements, and then using javascript to change the style back to visible after page load, is that people who don't have javascript enabled will never get to see those elements. So it's a solution which does not degrade gracefully.

A better way therefore, is to use javascript to both initially hide as well as redisplay those elements after page load. Using jQuery, we might be tempted to do something like this: 

$(document).ready(function() {
    $('body').hide();
    $(window).on('load', function() {
        $('body').show();
    });
});

However, if your page is very big with a lot of elements, then this code won't be applied soon enough (the document body won't be ready soon enough) and you might still see a FOUC. However, there is one element that we CAN hide as soon as script is encountered in the head, even before the document is ready: the HTML tag. So we could do something like this:

<html>
  <head>
  <!-- Other stuff like title and meta tags go here -->
  <style type="text/css">
    .hidden {display:none;}
  </style>
  <script type="text/javascript" src="/scripts/jquery.js"></script>
  <script type="text/javascript">
    $('html').addClass('hidden');
    $(document).ready(function() {    // EDIT: From Adam Zerner's comment below: Rather use load: $(window).on('load', function () {...});
      $('html').show();  // EDIT: Can also use $('html').removeClass('hidden'); 
     });  
   </script>
   </head>
   <body>
   <!-- Body Content -->
   </body>
</html>

Note that the jQuery addClass() method is called *outside* of the .ready() (or better, .on('load')) method.

user_8881770

This is the one that has worked for me and does not require javascript and it works great for pages with many elements and lots of css:

First, add a dedicated <STYLE> setting for the <HTML> tag with visibility 'hidden' and opacity as '0' at the top of your HTML, e.g, in the beginning of the <HEAD> element, for example, at the top of your HTML add:

<!doctype html>
<html>
<head>
    <style>html{visibility: hidden;opacity:0;}</style>

Then, at the end of your last .css stylesheet file, set the visibility and opacity styles to 'visible' and '1', respectively:

html {
    visibility: visible;
    opacity: 1;
}

If you already have an existing style block for the 'html' tag, then move the entire 'html' style to the end of the last .css file and add the 'visibility' and 'opacity' tags as described above.

https://gist.github.com/electrotype/7960ddcc44bc4aea07a35603d1c41cb0

user_31289420

An other quick fix which also works in Firefox Quantum is an empty <script> tag in the <head>. This however, penalizes your pagespeed insights and overall load time.

I had 100% success with it. I think it's also the main reason, why above solutions with other JS in the works.

<script type="text/javascript">

</script>
user_77101010

A simple solution to avoid a flash of unstyled content without javascript:

<!DOCTYPE html>
<html>
<head>
    <title>Bla bla</title>
    <link href="..." rel="stylesheet" />
    <link href="..." rel="stylesheet" />
</head>
<body style="opacity: 0">
    <!-- All HTML content here -->
    <script src="..."></script>
    <script src="..."></script>
    <style>
        body {
            opacity: 1 !important;
        }
    </style>
</body>
</html>

When the parser arrives at the body, it is faded out using "opacity: 0". When the parser finally arrives at the very bottom after everything else is parsed, the body is faded in again using an in-page style. The !important keyword there is important ;-), because it overrules the previous inline style of the body tag.

In this case, using "opacity: 0" to fade out is better than "display: none", because if you have layout operations done by javascript, they may not work when the affected element is not rendered.

That worked for me.

user_20406850

Here is my code .. hope it solve your problem

set <body style="opacity:0;">

<script>
    $(document).ready(function() {
        $("body").css('opacity', 1);
    });
</script>
user_118841980

I came up with a way that requires no real code change whatsoever, woohoo! My issue was related to importing several css files AFTER some javascript files.

To resolve the issue I just moved my CSS links so that they would be above my javascript imports. This allowed all my CSS to be imported and ready to go ASAP, so that when the HTML appears on the screen, even if the JS isn't ready, the page will be properly formatted

user_51758020

Every answer on this page slows down the load and it only hides the underlying issue. If you're experiencing FOUC, find out WHY it's happening and fix that.

At the core, this is happening:

  • because your stylesheets are not being loaded correctly: they should be loaded via link tag in the HTML, not via JavaScript
  • because you placed script tags before link tags, which may force a "layout operation" and trick the browser into rendering before it even attempts to load the style.

For reference, here's an example of FOUC:

FOUC example

user_2889060

The best solution I found till now is like this:

  1. Add all styles of your header to a <style/> tag in <head/>

  2. at the top of style tag add .not-visible-first{visibility: hidden} + other header style

  3. Add css via JS at the end of body

    document.getElementsByTagName("head")[0].insertAdjacentHTML("beforeend","<link rel=\"stylesheet\" href=\"/css/main.min.css?v=1.2.4338\" />");

  4. And remember to add .not-visible-first{visibility: visible} to the end of main.min.css

This option will create better user experience

user_61701910

You could try this with vanilla

function js_method(){
//todos
var elementDiv = document.getElementById("main");
elementDiv.style.display ="block";
}
<body onload="js_method()" id="main" style="display:none">
//todos
<h2>Hello</h2>
</body>

user_74689240
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