How do I get a div to automatically adjust to the size of the background I set for it without setting a specific height (or min-height) for it?

Solution 1

There is a very nice and cool way to make a background image work like an img element so it adjust its height automatically. You need to know the image width and height ratio. Set the height of the container to 0 and set the padding-top as percentage based upon the image ratio.

It will look like the following:

div {
    background-image: url('http://www.pets4homes.co.uk/images/articles/1111/large/feline-influenza-all-about-cat-flu-5239fffd61ddf.jpg');
    background-size: contain;
    background-repeat: no-repeat;
    width: 100%;
    height: 0;
    padding-top: 66.64%; /* (img-height / img-width * container-width) */
                /* (853 / 1280 * 100) */
}

You just got a background image with auto height which will work just like an img element. Here is a working prototype (you can resize and check the div height): http://jsfiddle.net/8m9ur5qj/

Solution 2

Another, perhaps inefficient, solution would be to include the image under an img element set to visibility: hidden;. Then make the background-image of the surrounding div the same as the image.

This will set the surrounding div to the size of the image in the img element but display it as a background.

<div style="background-image: url(http://your-image.jpg);">
 <img src="http://your-image.jpg" style="visibility: hidden;" />
</div>

Solution 3

There is no way to auto adjust for background image size using CSS.

You can hack around it by measuring the background image on the server and then applying those attributes to the div, as others have mentioned.

You could also hack up some javascript to resize the div based on the image size (once the image has been downloaded) - this is basically the same thing.

If you need your div to auto-fit the image, I might ask why don't you just put an <img> tag inside your div?

Solution 4

This answer is similar to others, but is overall the best for most applications. You need to know the image size before hand which you usually do. This will let you add overlay text, titles etc. with no negative padding or absolute positioning of the image. They key is to set the padding % to match the image aspect ratio as seen in the example below. I used this answer and essentially just added an image background.

.wrapper {
  width: 100%;
  /* whatever width you want */
  display: inline-block;
  position: relative;
  background-size: contain;
  background: url('https://upload.wikimedia.org/wikipedia/en/thumb/6/67/Wiki-llama.jpg/1600px-Wiki-llama.jpg') top center no-repeat;
  margin: 0 auto;
}
.wrapper:after {
  padding-top: 75%;
  /* this llama image is 800x600 so set the padding top % to match 600/800 = .75 */
  display: block;
  content: '';
}
.main {
  position: absolute;
  top: 0;
  bottom: 0;
  right: 0;
  left: 0;
  color: black;
  text-align: center;
  margin-top: 5%;
}
<div class="wrapper">
  <div class="main">
    This is where your overlay content goes, titles, text, buttons, etc.
  </div>
</div>

Solution 5

Maybe this can help, it's not exactly a background, but you get the idea:

<style>
div {
    float: left;
    position: relative;
}
div img {
    position: relative;
}

div div {
    position: absolute;
    top:0;
    left:0;
}
</style>

<div>
    <img src="http://antwrp.gsfc.nasa.gov/apod/image/0903/omegacen_davis.jpg" />
    <div>Hi there</div>
</div>

Solution 6

I looked at some of the solutions and they're great but I think I found a surprisingly easy way.

First, we need to get the ratio from the background image. We simply divide one dimension through another. Then we get something like for example 66.4%

When we have image ratio we can simply calculate the height of the div by multiplying the ratio by viewport width:

height: calc(0.664 * 100vw);

To me, it works, sets div height properly and changes it when the window is resized.

Solution 7

Pretty sure this will never been seen all the way down here. But if your problem was the same as mine, this was my solution:

.imaged-container{
  background-image:url('<%= asset_path("landing-page.png") %> ');
  background-repeat: no-repeat;
  background-size: 100%;
  height: 65vw;
}

I wanted to have a div in the center of the image, and this will allow me of that.

Solution 8

There is a pure CSS solution that the other answers have missed.

The "content:" property is mostly used to insert text content into an element, but can also be used to insert image content.

.my-div:before {
    content: url("image.png");
}

This will cause the div to resize its height to the actual pixel size of the image. To resize the width too, add:

.my-div {
    display: inline-block;
}

Solution 9

The recently introduced CSS aspect-ratio attribute (~2020-2021) is a great way to do this without padding hacks and is supported on all evergreen browsers.

Since we need to know the aspect ratio of the image ahead of time, and in many usecases you'll be able to predetermine the image dimension ratio ahead of time (but not always for user generated content), you can either hardcode a single style or inline the css when necessary.

aspect-ratio will calculate the height when the width is specified, based on the provided ratio (or calculate width, if the height is specified).

div {
    aspect-ratio: 3 / 2; /*common ratio, like an 800*600px image */

    width: 200px; /* computed height will be 133.33px, which is width/aspect-ratio */
    background: red; /* so any image bleed is shown*/
    background-image: url('https://images.unsplash.com/photo-1631163190830-8770a0ad4aa9?ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=200&q=80');
}
<div></div>

Solution 10

You can do it server side: by measuring the image and then setting the div size, OR loading the image with JS, read it's attributes and then set the DIV size.

And here is an idea, put the same image inside the div as an IMG tag, but give it visibility: hidden + play with position relative+ give this div the image as background.

Solution 11

I had this issue and found Hasanavi's answer but I got a little bug when displaying the background image on a wide screen - The background image didn't spread to the whole width of the screen.

So here is my solution - based on Hasanavi's code but better... and this should work on both extra-wide and mobile screens.

/*WIDE SCREEN SUPPORT*/
@media screen and (min-width: 769px) { 
    div {
        background-image: url('http://www.pets4homes.co.uk/images/articles/1111/large/feline-influenza-all-about-cat-flu-5239fffd61ddf.jpg');
        background-size: cover;
        background-repeat: no-repeat;
        width: 100%;
        height: 0;
        padding-top: 66.64%; /* (img-height / img-width * container-width) */
                    /* (853 / 1280 * 100) */
    }
}

/*MOBILE SUPPORT*/
@media screen and (max-width: 768px) {
    div {
        background-image: url('http://www.pets4homes.co.uk/images/articles/1111/large/feline-influenza-all-about-cat-flu-5239fffd61ddf.jpg');
        background-size: contain;
        background-repeat: no-repeat;
        width: 100%;
        height: 0;
        padding-top: 66.64%; /* (img-height / img-width * container-width) */
                    /* (853 / 1280 * 100) */
    }
}

As you might have noticed, the background-size: contain; property doas not fit well in extra wide screens, and the background-size: cover; property does not fit well on mobile screens so I used this @media attribute to play around with the screen sizes and fix this issue.

Solution 12

This Worked For Me:

background-image: url("/assets/image_complete_path");
background-position: center; /* Center the image */
background-repeat: no-repeat; /* Do not repeat the image */
background-size: cover;
height: 100%;

Solution 13

If it is a single predetermined background image and you want the div to to be responsive without distorting the aspect ratio of the background image you can first calculate the aspect ratio of the image and then create a div which preserves it's aspect ratio by doing the following:

Say you want an aspect ratio of 4/1 and the width of the div is 32%:

div {
  width: 32%; 
  padding-bottom: 8%; 
}

This results from the fact that padding is calculated based on the width of the containing element.

Solution 14

How about this :)

.fixed-centered-covers-entire-page{
    margin:auto;
    background-image: url('https://i.imgur.com/Ljd0YBi.jpg');
    background-repeat: no-repeat;background-size:cover;
    background-position: 50%;
    background-color: #fff;
    left:0;
    right:0;
    top:0;
    bottom:0;
    z-index:-1;
    position:fixed;
}
<div class="fixed-centered-covers-entire-page"></div>

Demo: http://jsfiddle.net/josephmcasey/KhPaF/

Solution 15

I would do the reverse and place the image inside of the main div with a width of 100%, which will make both the div and image responsive to screen size,

Then add the content within an absolute positioned div with width and height of 100% inside of the main div.

<div class="main" style="position: relative; width: 100%;">
    <img src="your_image.png" style="width: 100%;">
    <div style="position: absolute; width: 100%; height: 100%; display: flex...">
            YOUR CONTENT
    </div>
</div>

Solution 16

Adding to the original accepted answer just add style width:100%; to the inner image so it will auto-shrink/expand for mobile devices and wont end up taking large top or bottom margins in mobile view.

<div style="background-image: url(http://your-image.jpg);background-position:center;background-repeat:no-repeat;background-size: contain;height: auto;">
 <img src="http://your-image.jpg" style="visibility: hidden; width: 100%;" />
</div>

Solution 17

May be this can help, it's not exactly a background, but you get the simple idea

    <style>
div {
    float: left;
    position: relative;
}
div img {
    position: relative;
}

div div {
    position: absolute;
    top:0;
    left:0;
}
</style>

<div>
    <img src="http://www.planwallpaper.com/static/images/recycled_texture_background_by_sandeep_m-d6aeau9_PZ9chud.jpg" />
    <div>Hello</div>
</div>

Solution 18

You can do something like that

<div style="background-image: url(http://your-image.jpg); position:relative;">
 <img src="http://your-image.jpg" style="opacity: 0;" />
<div style="position: absolute;top: 0;width: 100%;height: 100%;">my content goes here</div>
</div>

Solution 19

If you know the ratio of the image at build time, want the height based off of the window height and you're ok targeting modern browsers (IE9+), then you can use viewport units for this:

.width-ratio-of-height {
  overflow-x: scroll;
  height: 100vh;
  width: 500vh; /* width here is 5x height */
  background-image: url("http://placehold.it/5000x1000");
  background-size: cover;
}

Not quite what the OP was asking, but probably a good fit for a lot of those viewing this question, so wanted to give another option here.

Fiddle: https://jsfiddle.net/6Lkzdnge/

Solution 20

Suppose you have some thing like this:

<div class="content">
    ... // inner HTML
</div>

and you want add a background to it, but you do not know the dimension of the image.

I had a similar problem, and I solved it by using grid:

HTML

<div class="outer">
    <div class="content">
        ... // inner HTML
    </div>
    <img class="background" />
</div>

CSS

.outer{
    display: grid;
    grid-template: auto / auto;
    // or you can assign a name for this block
}
.content{
    grid-area: 1 / 1 / 2 / 2;
    z-index: 2;
}
.background{
    grid-area: 1 / 1 / 2 / 2;
    z-index: 1;
}

z-index is just for placing image actually at the background, you can of course place img.background above the div.content.

NOTE: it might cause the div.content has same height of the picture, so if div.content have any children that placed according to its height, you might want set a number not something like 'auto'.

Solution 21

inspired by the most liked answer, I ended up coming up with a solution using min-height and 'vw' unit

I had an image in a very unusual proportion

through experimentation I ended up using

    min-height: 36vw;

that value must change, according to the ratio of your image

css code used im my actual page:

    background:url('your-background-image-adress') center center no-repeat;
    background-size: 100%;
    background-position: top center;
    margin-top: 50px;
    width: 100%;
    min-height: 36vw;

code pen example https://codepen.io/viniciusrad/pen/GRNPXoL

Solution 22

Had this issue with the Umbraco CMS and in this scenario you can add the image to the div using something like this for the 'style' attribute of the div:

style="background: url('@(image.mediaItem.Image.umbracoFile)') no-repeat scroll 0 0 transparent; height: @(image.mediaItem.Image.umbracoHeight)px"

Solution 23

I have been dealing with this issue for a while and decided to write a jquery plugin to solve this problem. This plugin will find all the elements with class "show-bg" (or you can pass it your own selector) and calculate their background image dimensions. all you have to do is include this code, mark the desired elements with class="show

Enjoy!

https://bitbucket.org/tomeralmog/jquery.heightfrombg

Solution 24

The best solution i can think of is by specifying your width and height in percent . This will allow you to rezise your screen based on your monitor size. its more of responsive layout..

For an instance. you have

<br/>
<div> . //This you set the width percent to %100
    <div> //This you set the width percent to any amount . if you put it by 50% , it will be half
    </div>
 </div>

This is the best option if you would want a responsive layout, i wouldnt recommend float , in certain cases float is okay to use. but in most cases , we avoid using float as it will affect a quite of number of things when you are doing cross-browser testing.

Hope this helps :)

Solution 25

actually it's quite easy when you know how to do it:

<section data-speed='.618' data-type='background' style='background: url(someUrl) 
top center no-repeat fixed;  width: 100%; height: 40vw;'>
<div style='width: 100%; height: 40vw;'>
</div>
</section>

the trick is just to set the enclosed div just as a normal div with dimensional values same as the background dimensional values (in this example, 100% and 40vw).

Solution 26

I solved this using jQuery. Until new CSS rules allow for this type of behavior natively I find it is the best way to do it.

Setup your divs

Below you have your div that you want the background to appear on ("hero") and then the inner content/text you want to overlay on top of your background image ("inner"). You can (and should) move the inline styles to your hero class. I left them here so it's quick and easy to see what styles are applied to it.

<div class="hero" style="background-image: url('your-image.png'); background-size: 100%; background-repeat: no-repeat; width: 100%;">
    <div class="inner">overlay content</div>
</div>

Calculate image aspect ratio

Next calculate your aspect ratio for your image by dividing the height of your image by the width. For example, if your image height is 660 and your width is 1280 your aspect ratio is 0.5156.

Setup a jQuery window resize event to adjust height

Finally, add a jQuery event listener for window resize and then calculate your hero div's height based off of the aspect ratio and update it. This solution typically leaves an extra pixel at the bottom due to imperfect calculations using the aspect ratio so we add a -1 to the resulting size.

$(window).on("resize", function ()
{
    var aspect_ratio = .5156; /* or whatever yours is */
    var new_hero_height = ($(window).width()*aspect_ratio) - 1;
    $(".hero").height(new_hero_height);
}

Ensure it works on page load

You should perform the resize call above when the page loads to have the image sizes calculated at the outset. If you don't, then the hero div won't adjust until you resize the window. I setup a separate function to do the resize adjustments. Here's the full code I use.

function updateHeroDiv()
{
    var aspect_ratio = .5156; /* or whatever yours is */
    var new_hero_height = ($(window).width()*aspect_ratio) - 1;
    $(".hero").height(new_hero_height);
}

$(document).ready(function() 
{       
    // calls the function on page load
    updateHeroDiv(); 

    // calls the function on window resize
    $(window).on("resize", function ()
    {
        updateHeroDiv();        
    }
});

Solution 27

If you can make an image on Photoshop where the main layer has an opacity of 1 or so and is basically transparent, put that img in the div and then make the real picture the background image. THEN set the opacity of the img to 1 and add the size dimensions you want.

That picture is done that way, and you can't even drag the invisible image off the page which is cool.

Solution 28

just add to div

style="overflow:hidden;"