How do I center an image if it's wider than its container?

Normally, you center images with display: block; margin: auto, but if the image is larger than the container, it overflows to the right. How do I make it overflow to the both sides equally? The width of the container is fixed and known. The width of the image is unknown.

A pure css solution

Requiring one extra wrapper (tested in FireFox, IE8, IE7):

Improved Answer

There was a problem with the original answer (below). If the image is larger than the container that outer is centered on with it's auto margins, then it truncates the image on the left and creates excessive space on the right, as this fiddle shows.

We can resolve that by floating inner right and then centering from the right. This still truncates the img off the page to the left, but it does so by explicitly pushing it that way and then centers back off of that, the combination of which is what prevents the extra horizontal scroll on the right. Now we only get as much right scroll as we need in order to see the right part of the image.

Fiddle Example (Borders in fiddle are for demo only.)

Essential CSS

div.outer {
    width: 300px; /* some width amount needed */
    margin: 0 auto; 
    overflow: visible;
}
div.inner {
    position:relative;
    float: right; /* this was added and display removed */
    right: 50%;
}
div.inner img {
    position: relative; 
    right:-50%; /* this was changed from "left" in original */
}

If you desire no right scroll at all for wide images

Then using the above, also set whatever element wraps outer (like body or a third wrapper) to have overflow: hidden.

Original Idea (for History)

Fiddle Example (Borders in fiddle are for demo only.)

HTML

<div class="outer">
    <div class="inner">
        <img src="/yourimage.png">
    </div>
</div>

CSS

div.outer {
    width: 300px; /* some width amount needed */
    margin: 0 auto; 
    overflow: visible;
}
div.inner {
    display: inline-block; 
    position:relative; 
    right: -50%;
}
div.inner img {
    position: relative; 
    left:-50%; 
}

Here's a 2 line CSS solution (a couple more lines might be required for cross-browser support):

img {
    margin-left: 50%;
    transform: translateX(-50%);
}

HTML

​<div class="image-container">
  <img src="http://www.google.com/images/logo.gif" height="100" />
</div>​

CSS

.image-container {
    width: 150px;
    border: solid 1px red;
    margin:100px;
}

.image-container img {
    border: solid 1px green;
}

jQuery

$(".image-container>img").each(function(i, img) {
    $(img).css({
        position: "relative",
        left: ($(img).parent().width() - $(img).width()) / 2
    });
});

​

See it on jsFiddle: http://jsfiddle.net/4eYX9/30/

Alternative pure CSS solution is to use transform attribute:

HTML:

<div class="outer">
    <img class="image" src="http://www.gstatic.com/webp/gallery/4.jpg" />
</div>

CSS:

.outer {
    position: relative;
    width: 100px;
    border: 1px solid black;
    height: 150px;
    margin-left: 100px; /* for demo */
    /* overflow: hidden; */
}

img.image {
    width: 200px;
    opacity: 0.7;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    -webkit-transform: translateX(-50%);
}

Fiddle

Just to add a overflow:hidden to parent div to hide the extra area of the image.

Your best bet is to set it as background image of the container instead.

#container {
    background: url('url/to/image.gif') no-repeat center top;
}