How To Change A CSS Background Image's Opacity - Viblo

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With CSS and CSS3 you can do a lot of things, but setting an opacity on a CSS background is not one of them. However, if you get creative, there are a ton of creative work-arounds you to make it seem like you’re changing the CSS background image’s opacity. Both of the following methods have excellent browser support down to Internet Explorer 8.

Method 1: Use absolute positioning and an image

This method is exactly like it sounds. You simply use absolute positioning on an a normal img tag and make it seem like you used the CSS background-image property. All you have to do is put the image inside of a position: relative; container. Here’s what the HTML markup generally looks like:

<div class="my-container"> <h1>Scotch Scotch Scotch</h1> <img src="http://placekitten.com/1500/1000"> </div>

And here’s what your CSS will look like:

.my-container { position: relative; overflow: hidden; } .my-container h1 { padding: 200px; position: relative; z-index: 2; } .my-container img { position: absolute; left: 0; top: 0; width: 100%; height: auto; opacity: 0.6; }

Finally, here’s a nice little demo on CodePen: http://codepen.io/ncerminara/pen/tncAi

Method 2: Using CSS Pseudo-Elements

This method is seems simple once you see it, and is definitely my preferred method of doing this. Using CSS pseudo-elements of either :before or :after, you a div with a background image and set an opacity on it. Here’s what your HTML markup would roughly look like:

<div class="my-container"> <h1>Scotch Scotch Scotch</h1> </div>

And here’s what the CSS looks like:

.my-container { position: relative; background: #5C97FF; overflow: hidden; } /* You could use :after - it doesn't really matter */ .my-container:before { content: ' '; display: block; position: absolute; left: 0; top: 0; width: 100%; height: 100%; z-index: 1; opacity: 0.6; background-image: url('http://placekitten.com/1500/1000'); background-repeat: no-repeat; background-position: 50% 0; -ms-background-size: cover; -o-background-size: cover; -moz-background-size: cover; -webkit-background-size: cover; background-size: cover; }

Finally, here’s a nice little demo of this method:

data-theme-id=”0″ data-slug-hash=”eFzJI” data-default-tab=”result” data-user=”ncerminara” class=’codepen’> See the Pen How to Change a CSS Background Image’s Opacity by Nicholas Cerminara (@ncerminara) on CodePen.

https://scotch.io/tutorials/how-to-change-a-css-background-images-opacity

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