Html – How to give text or an image a transparent background using CSS

csshtmlopacity

Is it possible, using CSS only, to make the background of an element semi-transparent but have the content (text & images) of the element opaque?

I'd like to accomplish this without having the text and the background as two separate elements.

When trying:

p {
  position: absolute;
  background-color: green;
  filter: alpha(opacity=60);
  opacity: 0.6;
}

span {
  color: white;
  filter: alpha(opacity=100);
  opacity: 1;
}

<p>
  <span>Hello world</span>
</p>

It looks like child elements are subjected to the opacity of their parents, so opacity:1 is relative to the opacity:0.6 of the parent.

Best Answer

Either use a semi-transparent PNG or SVG image or use CSS:

background-color: rgba(255, 0, 0, 0.5);

Here's an article from css3.info, Opacity, RGBA and compromise (2007-06-03).

<p style="background-color: rgba(255, 0, 0, 0.5);">
  <span>Hello, World!</span>
</p>

Related Solutions

Html – Vertically align text next to an image

Actually, in this case it's quite simple: apply the vertical align to the image. Since it's all in one line, it's really the image you want aligned, not the text.

<!-- moved "vertical-align:middle" style from span to img -->
<div>
  <img style="vertical-align:middle" src="https://via.placeholder.com/60x60">
  <span style="">Works.</span>
</div>

Tested in FF3.

Now you can use flexbox for this type of layout.

.box {
   display: flex;
   align-items:center;
}

<div class="box">
    <img src="https://via.placeholder.com/60x60">
    <span style="">Works.</span>
</div>

Html – When to use IMG vs. CSS background-image

Proper uses of IMG

Use IMG if you intend to have people print your page and you want the image to be included by default. —JayTee
Use IMG (with alt text) when the image has an important semantic meaning, such as a warning icon. This ensures that the meaning of the image can be communicated in all user-agents, including screen readers.

Pragmatic uses of IMG

Use IMG plus alt attribute if the image is part of the content such as a logo or diagram or person (real person, not stock photo people). —sanchothefat
Use IMG if you rely on browser scaling to render an image in proportion to text size.
Use IMG for multiple overlay images in IE6.
~~Use IMG with a z-index in order to stretch a background image to fill its entire window.~~
Note, this is no longer true with CSS3 background-size; see #6 below.
Using img instead of background-image can dramatically improve performance of animations over a background.

When to use CSS background-image

Use CSS background images if the image is not part of the content. —sanchothefat
Use CSS background images when doing image-replacement of text eg. paragraphs/headers. —sanchothefat
Use background-image if you intend to have people print your page and you do not want the image to be included by default. —JayTee
Use background-image if you need to improve download times, as with CSS sprites.
Use background-image if you need for only a portion of the image to be visible, as with CSS sprites.
Use background-image with background-size:cover in order to stretch a background image to fill its entire window.