How do I make a semi transparent background? - css

Question

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

Answer 1

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.

Answer 2

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;
}

Answer 3

If you want to make transparent background is gray, pls try:
.transparent{
background:rgba(1,1,1,0.5);
}

Answer 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.

Answer 5

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.

Answer 6

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">Example</h1>

Answer 7

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
}

Answer 8

This is simple and sort. Use hsla css function like below
.transparent {
background-color: hsla(0,0%,4%,.4);
}

Answer 9

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