How to get div height to auto-adjust to background size?

Question

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?

Febrifuge

please see my answer here: https://mcmap.net/q/76135/-make-div-as-high-as-background-image – Blackpool

Answer 1

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>

Chipman

not exactly useful since the image will use the 'space' and content will looks like having a great margin top. – Crescantia

Sorry, can't edit my previous comment so just to add to it: I can get the image to resize nicely by setting background-size on the div to 100% and max-width on the (hidden) image to 100% – Alverson

Perhaps I'm missing something, but if you're going to put an img into your markup anyway, why not simply not hide the actual <img> and not bother with a background-image either? What advantage is there to doing things this way? – Belomancy

I have posted an answer that allows you to still overlay text etc. over the background image quite easily and doesnt require you to add an unnecessary image tag. – Unpen

Good answer, but doesn't the browser have to load it twice then? – Peugia

@Peugia When you say load, what exactly do you mean? Once the image has downloaded, it is presumably cached. From that point, any other requests are based on a local copy. So, no. It is not downloaded twice. But, it is loaded twice. – Chipman

Sorry forgot about the cache -- stupid me. Good answer. – Peugia

What if I want to change the image in the div based on which button a user clicked in my page ? – Taunton

@MarkAmery I just implemented this solution. The reason is that I wanted the background-size: contain; effect which can't be replicated with a normal <img>. In my implementation, the <img> with width: 100% and height: auto (or vice versa) pushes that containing <div> until the <div>'s max-height and/or max-width is hit (using overflow: hidden so the <div> doesn't continue to expand). This emulates background-size: contain. – Dramatist

@MarkAmery One of the coolest things about background-image is that it can use CSS blend-modes, whereas img cannot. – Jarrettjarrid

I liked to use the background image instead of img for reasons of having to load a huge image, but only on desktop version. As browsers seemingly load images anyhow even if display is none doing a img switch via CSS has no sense as he anyhow loads both images. So one way for me was to load an empty transparent png to the img with the exact measures of the bg image. Then let the browser decide to load image by CSS. – Reimburse

I wanted to have a gradient in the background image, which cannot be done with normal <img /> tag, hence I had to use background-image css on a div. This solution works perfectly for me. – Gaiety

How this answer could accepted, can't believe it. As writer says, it's an inefficient way to achieve this. – Jemine

Nice way, it seems hacky but it's the best way I've ever seen! – Chelate

Answer 2

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/

Ireful

Indeed awesome! Just for future generations watching this answer, if you are using compass (scss), I created a mixin from this using their helper functions to do the calculations for you: @mixin div-same-size-as-background-img($url) { background-image: url($url); background-size: contain; background-repeat: no-repeat; width: 100%; height: 0; padding-top: percentage(image-height($url) / image-width($url)); } – Sikko

FYI to those who are wondering, the padding-top doesn't create a white space because it just adds height to the element. The image is a background image, so it shows with proper positioning and spacing. It's pretty stupid we have to come up with tricks like these for CSS. – Jeffryjeffy

Worked really well for me too! Love it. Only downside is that if you want to put a title in the element holding the background image, it is pushed down so you would have to negatively position that element to get it back in the boundaries of the image again. Not undoable :) – Selenaselenate

Unfortunately, the padding-top doesn't allow you to put anything else in the div, such as form elements over the background. – Obstruct

@GaryHayes you can set position:relative to the div and put another div inside with position:absolute; top:0; bottom:0; left:0; right:0;set – Torey

Although this method works for showing a background image, it does render the div itself less useful by filling it with padding. Kryptik suggested adding an absolutely positioned div inside the container, but then why bother with a background image? You could then just use an actual image in the content div if you're going to just absolute-position everything over it. This defeats the purpose of using a background image in the first place. – Shumate

Ultimately, I ended up splitting the padding calculation in half again and separating it to the top and bottom (ie. padding: 61.805% 0% 61.805% 0%;). This way at least the content that I intended to have over the background image is in the middle of the div to start rather than pushed all the way past the bottom. This still takes some negative margins to work, though. – Shumate

What if I don't want to calculate the percentages for each image and don't want to use any javascript ? I guess the selected answer is better. Could it increase the page load time ? – Taunton

It works but will it work like the img-responsive class in an <img> tag? – Boardwalk

Use padding-bottom instead if you want to put content inside the div without using relative/absolute positioning (most frequently used for email templates) – Cheery

FYI, the easiest way I've found to put content in the div is to have an inner div with the following styling: margn-top: -30%; /* inverse of the padding-top of the background container */ width: 100%; – Butadiene

Just a quick question! What if my image is a square? My padding will be 100%?! =O – Parson

I don't understand the padding calculation. The answer says 853 / 1280 * 100 which is equal to 0.006664. What is container-width in that equation? A percent value? A pixel value? Why does the calculation not equal to what's in the code presented? – Ajar

@Parson sure - it's 100% of the width of the parent container. Padding % are always relative to the parent's width. – Canvasback

@billynoah 853 / 1280 * 100 equals 66.64. You may have multiplied before dividing. – Canvasback

@Canvasback - lolol.. you're right. Good old order of operations. – Ajar

The comment on the padding-top property should be /* img-height / img-width * 100 */ – Grassquit

as @Shumate has pointed out you can cut the height in half to fit something inside, I would add that you can place a centered element inside the container by using flex and align the items in the center (instead of dealing with negative margins) – Vassili

This works great and is responsive with calc: padding-top: calc(1707 / 1280 * 100%); – Herwick

Answer 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?

Galop

Thanks - but I need it as background so the image trick won't do it. i guess I am gonna hack up some javascript as you say worst case scenario but it's probably not worth it. – Febrifuge

^^ That's probably not a good idea. The browser may take several seconds before your image gets downloaded, and you can't measure it until then, so your div will be hanging out at the wrong size for quite some time! – Galop

He could just run the JavaScript when the document is ready then. – Fiddlestick

You can't change the src of an img with media queries, but you can change the file used as a background image with media queries. – Polyvalent

Answer 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>

Unpen

-1 for use of !important - and linking out to another answer. Please consider copying in the relevant code from the other answer (with attribution)i so that this one is more complete, and incase of link rot. – Aphelion

@jammypeach is this better? – Unpen

@Unpen unless I'm missing something this doesn't scale the image. It just masks it. – Gyrostabilizer

@Gyrostabilizer Strangely enough all background calls need to be in the one element. I found it was cropping when I specified the "background: url()" on a specific id and "background-size: contain" in a general class. – Anabas

@Gyrostabilizer Update: I was able to fix that issue by using "background-image: url()" instead of "background: url()". – Anabas

Answer 5

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.

Uvular

yes, it's a neat trick, but if the image dimensions are already known, why not use simply the height from the image? i think what we are looking for is a solution that works with any image, without hardcoding numbers... – Heterograft

and also the growing and shrinking of the height based on screen size is also not always desirable – Heterograft

Great solution : It is responsive to the size of the browser, and you can still use with flex box display. I'll try this for my problem now and see if I can complete my work. Cheers! – Declamation

However, I would be interested to understand why multiplying the image ratio to 100vw makes it work. Cheers! – Declamation

Answer 6

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>

Manducate

please explain why you kept position of img as relative ? – Denudate

Probably because the float: left; broke his positioning – Curtal

Answer 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.

Monsoon

Answer 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;
}

Nelly

I like this solution, but when the browser is made smaller there there is a lot of white space left below the header image which is set to be responsive. – Donee

that's a lit one answer ❤ – Eaton

Answer 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 {
    /*common ratio, like an 800*600px image */
    aspect-ratio: 3 / 2;
    /* computed height will be 133.33px, which is width/aspect-ratio */
    width: 200px;
    /* red BG for debugging so any image bleed is shown*/
    background: red; 
    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>

Olympium

Thank you for taking the effort to leave this comment here. – Mcmanus

Holy crap, they finally added an aspecit-ratio attribute?? I remember a couple of years ago struggling my ass off with something that would've been easily solved by this, but I ended up having to JS it, IIRC. Thanks for this! – Ochlophobia

Answer 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.

Wenzel

lol why require server side? It should be able to be implement with CSS. – Lovelady

@Lovelady hahaha - check the year I answered – Wenzel

@ItayMoav-Malimovka hehe, didn't notice that. – Lovelady

Answer 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.

Higherup

Answer 12

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>

Heintz

Answer 13

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%;

Bootless

this could be shortened to background: url("/assets/image_complete_path") no-repeat center / cover; height: 100%; – Psychoneurotic

Answer 14

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>

Ahmednagar

Answer 15

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.

Immersionism

Answer 16

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/

Clutch

Answer 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>

Benzine

Answer 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>

Nettlesome

Answer 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/

Spirogyra

Answer 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'.

Fauces

Answer 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

Meenen

Answer 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"

Tullus

Answer 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

Jeth

Answer 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 :)

Obscene

Answer 25

If the image height can vary or if you don't know exactly the height of the image, with a little bit of jquery, and css you can solve this:

HTML

<div class="bg-cover" style="background-image:url(https://i.imgur.com/Ljd0YBi.jpg);"></div>

JQUERY

<script>
var image_url = $('.bg-cover').css('background-image'),
image;

// Remove url() or in case of Chrome url("")
image_url = image_url.match(/^url\("?(.+?)"?\)$/);

if (image_url[1]) {
image_url = image_url[1];
image = new Image();

// just in case it is not already loaded
$(image).load(function() {
//alert(image.width + 'x' + image.height);
$('.bg-cover').css('min-height', image.height);
});

image.src = image_url;
}
</script>

Ekaterinodar

Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center. – Ytterbium

Answer 26

In order to set the height of an "empty" container element to be aligned with the size of its background image, you simply need to perform a small calculation of ratio and set the height accordingly.

For example:

Let's say the background image size is 1920x600.

The ratio of the width and the height is 3.2 (1920 / 600).

The next step is to set the height of the container element with the background image in it to be according to the current view width:

div.container {
width: 100vw;    
height: calc(100vw / 3.2)
}

So, if the current view width is 1600px for example, the height will be 500px, and the background image will fit right in and the height will be exactly right.

Unison

Answer 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.

Everetteverette

Answer 28

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).

Wagonlit

You're setting the height to be a proportion of the window width. This won't work in all cases - and some of your content, like data-speed has nothing to do with your answer. – Aspia

Aren't most things "quite easy when you know how to do it"? – Polyvalent

Answer 29

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();        
    }
});

Pianist

New CSS has been added! aspect-ratio – Olympium

@Olympium nice! This answer was from long ago and I knew improvements would come with time. – Pianist

Finally, 5 years later – Olympium

I tried to reply with simply "ha!" except 15 chars were required for a comment—hence this whole sentence. – Pianist

Answer 30

just add to div

style="overflow:hidden;"

Moneychanger