How do I make a semi transparent background?

Question

I need to make a white background 50% transparent without affecting anything else. How do I do it?

here is a link to an article that describes the method for implementing transparency using CSS. http://www.domedia.org/oveklykken/css-transparency.php Beware though it seems that cross browser support can be an issue which may cause you to change your implementation. — Bnjmn, Jan 25 '11 at 06:24
Do you mean how to set an opacity to a div background without affecting the nested elements? — Ben, Jan 25 '11 at 06:31
Possible duplicate of [How do I give text or an image a transparent background using CSS?](http://stackoverflow.com/questions/806000/how-do-i-give-text-or-an-image-a-transparent-background-using-css) — danicotra, Oct 30 '16 at 19:53
See: http://stackoverflow.com/questions/806000/how-do-i-give-text-or-an-image-a-transparent-background-using-css — danicotra, Oct 30 '16 at 20:01

score 372 · Accepted Answer · edited Mar 02 '20 at 19:51

372

Use rgba():

.transparent {
  background-color: rgba(255,255,255,0.5);
}

This will give you 50% opacity while the content of the box will continue to have 100% opacity.

If you use opacity:0.5, the content will be faded as well as the background. Hence do not use it.

edited Mar 02 '20 at 19:51

Sean

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answered Jan 25 '11 at 08:50

Tarun

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yes, IE supports rgba, its syntax is #ARGB and is written as filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#AARRGGBBAA,endColorstr=#AARRGGBBAA); its basically a gradient of a static color but with transparency. – Tarun Jan 27 '11 at 05:23
Change `background:` with `background-color:` – Gabrielizalo May 07 '19 at 19:39
`background-color` is not more correct than `background`. – Sean Feb 24 '20 at 21:23
@Sean Is it more specific and intention-revealing, then? Personally I prefer to use it in this case, but is there a reason that's not a good preference? – Dave Slutzkin Feb 24 '20 at 23:23
1

@DaveSlutzkin It's a fine preference to have and there's nothing wrong with it, but edits should not be made based on personal preference. Otherwise, questions will keep oscillating between different versions as people with opposing preferences encounter them. – Sean Feb 25 '20 at 14:06

score 16 · Answer 2 · edited Feb 24 '20 at 21:25

16

This works, but all the children of the element with this class will also become transparent, without any way of preventing that.

.css-class-name {
    opacity:0.8;
}

edited Feb 24 '20 at 21:25

Sean

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answered Jan 07 '15 at 09:50

umesh pathak

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score 13 · Answer 3 · answered Jun 30 '16 at 06:24

13

If you want to make transparent background is gray, pls try:

   .transparent{
       background:rgba(1,1,1,0.5);
   }

answered Jun 30 '16 at 06:24

ThomasDuc

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score 4 · Answer 4 · answered Jan 25 '11 at 08:46

4

Good to know

Some web browsers have difficulty to render text with shadows on top of transparent background. Then you can use a semi transparent 1x1 PNG image as a background.

Note

Remember that IE6 don’t support PNG files.

answered Jan 25 '11 at 08:46

Joacim Nitz

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IE6 does support PNGs, even transparent ones: filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, sizingMethod=scale, src='/filename.png'); – manmal Jan 01 '12 at 18:05
@manmal but where do you put your IE fix? Directly in the site .css file? – Thalatta Dec 15 '14 at 20:00
1

@Thalatta yes, just try it. – manmal Dec 17 '14 at 08:16

score 3 · Answer 5 · answered Aug 04 '11 at 02:54

DO NOT use a 1x1 semi transparent PNG. Size the PNG up to 10x10, 100x100, etc. Whatever makes sense on your page. (I used a 200x200 PNG and it was only 0.25 kb, so there's no real concern over file size here.)

After visiting this post, I created my web page with 3, 1x1 PNGs with varying transparency.

Dreamweaver CS5 was tanking. I was having flash backs to DOS!!! Apparently any time I tried to scroll, insert text, basically do anything, DW was trying to reload the semi transparent areas 1x1 pixel at a time ... YIKES!

Adobe tech support didn't even know what the problem was, but told me to rebuild the file (it worked on their systems, incidentally). It was only when I loaded the first transparent PNG into the css file that the doc dove deep again.

Then I found a post on another help site about PNGs crashing Dreamweaver. Size your PNG up; there's no downside to doing so.

Sizing up a PNG just because your tool is so crappy that it doesn't support it? Really... — jurchiks, Feb 23 '15 at 15:16

score 0 · Answer 6 · answered May 02 '17 at 14:40

Although dated, not one answer on this thread can be used universally. Using rgba to create transparent color masks - that doesn't exactly explain how to do so with background images.

My solution works for background images or color backgrounds.

#parent {
    font-family: 'Open Sans Condensed', sans-serif;
    font-size: 19px;
    text-transform: uppercase;
    border-radius: 50%;
    margin: 20px auto;
    width: 125px;
    height: 125px;
    background-color: #476172;
    background-image: url('https://unsplash.it/200/300/?random');
    line-height: 29px;
    text-align:center;
}

#content {
    color: white;
    height: 125px !important;
    width: 125px !important;
    display: table-cell;
    border-radius: 50%;
    vertical-align: middle;
    background: rgba(0,0,0, .3);
}

<h1 id="parent"><a href="" id="content" title="content" rel="home">Example</a></h1>

score 0 · Answer 7 · edited Jan 31 '18 at 07:24

0

div.main{
     width:100%;
     height:550px;
     background: url('https://images.unsplash.com/photo-1503135935062-
     b7d1f5a0690f?ixlib=rb-enter code here0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=cf4d0c234ecaecd14f51a2343cc89b6c&dpr=1&auto=format&fit=crop&w=376&h=564&q=60&cs=tinysrgb') no-repeat;
     background-position:center;
     background-size:cover 
}
 div.main>div{
     width:100px;
     height:320px;
     background:transparent;
     background-attachment:fixed;
     border-top:25px solid orange;
     border-left:120px solid orange;
     border-bottom:25px solid orange;
     border-right:10px solid orange;
     margin-left:150px 
}

enter image description here

edited Jan 31 '18 at 07:24

Rob

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answered Jan 31 '18 at 07:22

Abhi Sharma

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Thank you for this code snippet, which might provide some limited, immediate help. A [proper explanation would greatly improve its long-term value](//meta.stackexchange.com/q/114762/350567) by showing *why* this is a good solution to the problem, and would make it more useful to future readers with other, similar questions. Please [edit] your answer to add some explanation, including the assumptions you've made. – iBug Jan 31 '18 at 07:29

score 0 · Answer 8 · answered Feb 12 '21 at 13:03

0

This is simple and sort. Use hsla css function like below

.transparent {
   background-color: hsla(0,0%,4%,.4);
}

answered Feb 12 '21 at 13:03

Nainish Modi

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score -2 · Answer 9 · answered Jan 25 '11 at 06:23

-2

Try this:

.transparent
{ 
  opacity:.50;
  -moz-opacity:.50; 
  filter:alpha(opacity=50); 
}

answered Jan 25 '11 at 06:23

Chandu

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this will make content have 50% opacity as well. – Tarun Jan 25 '11 at 08:49
This can easily be fixed by the css: `.transparent * { opacity:1; }`, unless, for example, an element with the `transparent` class has inner html – Tim Cooke Sep 13 '16 at 02:34

How do I make a semi transparent background?

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