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Set size on background image with CSS?


Question

Is it possible to set the size of the background image with CSS?

I want to do something like:

background: url('bg.gif') top repeat-y;
background-size: 490px;

But it seems it's totally wrong to do it like that...

2014/05/05
1
387
5/5/2014 12:32:02 PM

Accepted Answer

CSS2

If you need to make the image bigger, you must edit the image itself in an image editor.

If you use the img tag, you can change the size, but that would not give you the desired result if you need the image to be background for some other content (and it will not repeat itself like you seems to want)...

CSS3 unleash the powers

This is possible to do in CSS3 with background-size.

All modern browsers support this, so unless you need to support old browsers, this is the way to do it.
Supported browsers:
Mozilla Firefox 4.0+ (Gecko 2.0+), Microsoft Internet Explorer 9.0+, Opera 10.0+, Safari 4.1+ (webkit 532) and Chrome 3.0+.

.stretch{
/* Will stretch to specified width/height */
  background-size: 200px 150px;
}
.stretch-content{
/* Will stretch to width/height of element */
  background-size: 100% 100%;
}

.resize-width{
/* width: 150px, height: auto to retain aspect ratio */
  background-size: 150px Auto;
}
.resize-height{
/* height: 150px, width: auto to retain aspect ratio */
  background-size: Auto 150px;
}
.resize-fill-and-clip{ 
  /* Resize to fill and retain aspect ratio.
     Will cause clipping if aspect ratio of box is different from image. */ 
  background-size: cover;
}
.resize-best-fit{
/* Resize to best fit and retain aspect ratio.
   Will cause gap if aspect ratio of box is different from image. */ 
  background-size: contain;
}

In particular, I like the cover and contain values that gives us new power of control that we didn't have before.

Round

You can also use background-size: round that have a meaning in combination with repeat:

.resize-best-fit-in-repeat{
/* Resize to best fit in a whole number of times in x-direction */ 
  background-size: round auto; /* Height: auto is to keep aspect ratio */
  background-repeat: repeat;
}

This will adjust the image width so it fits a whole number of times in the background positioning area.


Additional note
If the size you need is static pixel size, it is still smart to physically resize the actual image. This is both to improve quality of the resize (given that your image software does a better job than the browsers), and to save bandwidth if the original image is larger than what to display.

2020/06/20
621
6/20/2020 9:12:55 AM


If your users use only Opera 9.5+, Safari 3+, Internet Explorer 9+ and Firefox 3.6+ then the answer is yes. Otherwise, no.

The background-size property is part of CSS 3, but it won't work on most browsers.

For your purposes just make the actual image larger.

2011/12/29

Not possible. The background will always be as large as it can be, but you can stop it from repeating itself with background-repeat.

background-repeat: no-repeat;

Secondly, the background does not go into margin-area of a box, so if you want to have the background only be on the actual contents of a box, you can use margin instead of padding.

Thirdly, you can control where the background image starts. By default it's the top left corner of a box, but you can control that with background-position, like this:

background-position: center top;

or perhaps

background-position: 20px -14px;

Negative positioning is used a lot with CSS sprites.

2009/08/27

Not too hard, if you're not afraid of going a little more in depth :)

There's one forgotten argument:

background-size: contain;

This won't stretch your background-image as it would do with cover. It would stretch until the longer side reaches the width or height of the outer container and therefore preserving the image.

Edit: There's also -webkit-background-size and -moz-background-size.

The background-size property is supported in IE9+, Firefox 4+, Opera, Chrome, and Safari 5+.

- Source: W3 Schools

2012/11/09

In support of the answer that @tetra gave, I want to point out that if the image is an SVG, then resizing the actual image is not necessary.

Since an SVG file is just XML you can specify whatever size you want it to appear within the XML.

However, if you are using the same SVG image in different places and need it to be different sizes, then using background-size is very helpful. SVG files are inherently smaller than raster images anyway and resizing on the fly with CSS can be very helpful without any performance cost that I am aware of, and certainly little to no loss of quality.

Here is a quick example:

<div class="hasBackgroundImage">content</div>

.hasBackgroundImage
{
    background: transparent url('/image/background.svg') no-repeat 10px 5px;
    background-size: 1.4em;
}

(Note: this works for me in OS X 10.7 with Firefox 8, Safari 5.1, and Chrome 16.0.912.63)

2012/01/10

background-size: 200px 50px change it to 100% 100% and it will scale on the needs of the content tag like ul li or div... tried it

2012/01/03

Source: https://stackoverflow.com/questions/1341358
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