`backdrop-filter` CSS property

The backdrop-filter CSS property lets you apply graphical effects such as blurring or color shifting to the area behind an element. Because it applies to everything behind the element, to see the effect the element or its background needs to be transparent or partially transparent.

Try it

backdrop-filter: blur(10px);

backdrop-filter: invert(80%);

backdrop-filter: sepia(90%);

<section class="default-example" id="default-example">
  <div class="example-container">
    <div id="example-element">Example</div>
  </div>
</section>

.example-container {
  background-image: url("/shared-assets/images/examples/balloon.jpg");
  background-size: cover;
  width: 200px;
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: black;
}

#example-element {
  font-weight: bold;
  flex: 1;
  text-align: center;
  padding: 20px 10px;
  background-color: rgb(255 255 255 / 0.2);
}

Syntax

css

/* Keyword value */
backdrop-filter: none;

/* URL to SVG filter */
backdrop-filter: url("common-filters.svg#filter");

/* <filter-function> values */
backdrop-filter: blur(2px);
backdrop-filter: brightness(60%);
backdrop-filter: contrast(40%);
backdrop-filter: drop-shadow(4px 4px 10px blue);
backdrop-filter: grayscale(30%);
backdrop-filter: hue-rotate(120deg);
backdrop-filter: invert(70%);
backdrop-filter: opacity(20%);
backdrop-filter: sepia(90%);
backdrop-filter: saturate(80%);

/* Multiple filters */
backdrop-filter: url("filters.svg#filter") blur(4px) saturate(150%);

/* Global values */
backdrop-filter: inherit;
backdrop-filter: initial;
backdrop-filter: revert;
backdrop-filter: revert-layer;
backdrop-filter: unset;

Values

none: No filter is applied to the backdrop.
<filter-value-list>: A space-separated list of <filter-function>s or an SVG filter that will be applied to the backdrop. CSS <filter-function>s include blur(), brightness(), contrast(), drop-shadow(), grayscale(), hue-rotate(), invert(), opacity(), saturate(), and sepia().

Description

The backdrop-filter property applies filter effects to the pixels painted behind an element, up to the nearest ancestor that is a backdrop root. Content above the backdrop root is not affected.

Backdrop root

A backdrop root is an element that establishes a boundary for backdrop-filter effects. The following elements are backdrop roots:

The root element (<html>)
An element with a filter value other than none
An element with an opacity value less than 1
An element with a mask, mask-image, mask-border, or clip-path value other than none
An element with a backdrop-filter value other than none
An element with a mix-blend-mode value other than normal
An element with will-change set to any of the above properties

This means that if a parent element has opacity: 0.9, it becomes a backdrop root and any child's backdrop-filter will only blur the content between that parent and the child - not the content behind the parent. This is a common source of confusion when backdrop-filter appears to have no visible effect despite being correctly applied.

The following example demonstrates how backdrop roots affect backdrop-filter. The first container has will-change: opacity, making it a backdrop root - notice that the blur circle only affects the text and square inside the container, not the checkered background behind it. The second container is not a backdrop root, so its blur circle affects everything behind it, including the page background.

html

<div class="parent backdrop-root">
  <div class="text">Text</div>
  <div class="square"></div>
  <div class="overlay"></div>
</div>
<div class="parent">
  <div class="text">Text</div>
  <div class="square"></div>
  <div class="overlay"></div>
</div>

css

body {
  display: flex;
  column-gap: 16px;
  padding: 16px;
  background-image: conic-gradient(
    gray 90deg,
    silver 90deg 180deg,
    gray 180deg 270deg,
    silver 270deg
  );
  background-size: 32px 32px;
}

.parent {
  position: relative;
  width: 256px;
  height: 256px;
}

.backdrop-root {
  outline: 2px solid crimson;
  will-change: opacity;
}

.square {
  position: absolute;
  top: 35px;
  left: 40%;
  width: 25%;
  height: 25%;
  border: 10px solid white;
}

.text {
  position: absolute;
  left: 40%;
  color: white;
  font-size: 32px;
  font-weight: 500;
  text-align: center;
  line-height: 256px;
  filter: blur(1px);
}

.overlay {
  position: absolute;
  top: 25%;
  left: 50%;
  width: 50%;
  height: 50%;
  outline: 3px solid gainsboro;
  border-radius: 9999px;
  backdrop-filter: blur(10px);
}

Formal definition

Initial value	`none`
Applies to	all elements; In SVG, it applies to container elements excluding the `<defs>` element and all graphics elements
Inherited	no
Computed value	as specified
Animation type	a filter function list

Formal syntax

backdrop-filter = 
  none                 |
  <filter-value-list>  

<filter-value-list> = 
  [ <filter-function> | <url> ]+  

<filter-function> = 
  <blur()>         |
  <brightness()>   |
  <contrast()>     |
  <drop-shadow()>  |
  <grayscale()>    |
  <hue-rotate()>   |
  <invert()>       |
  <opacity()>      |
  <sepia()>        |
  <saturate()>     

<blur()> = 
  blur( <length>? )  

<brightness()> = 
  brightness( [ <number> | <percentage> ]? )  

<contrast()> = 
  contrast( [ <number> | <percentage> ]? )  

<drop-shadow()> = 
  drop-shadow( [ <color>? && <length>{2,3} ] )  

<grayscale()> = 
  grayscale( [ <number> | <percentage> ]? )  

<hue-rotate()> = 
  hue-rotate( [ <angle> | <zero> ]? )  

<invert()> = 
  invert( [ <number> | <percentage> ]? )  

<opacity()> = 
  opacity( [ <number> | <percentage> ]? )  

<sepia()> = 
  sepia( [ <number> | <percentage> ]? )  

<saturate()> = 
  saturate( [ <number> | <percentage> ]? )

Examples

undefined

CSS

css

.box {
  background-color: rgb(255 255 255 / 30%);
  backdrop-filter: blur(10px);
}

body {
  background-image: url("anemones.jpg");
}

html,
body {
  height: 100%;
  width: 100%;
}

.container {
  background-size: cover;
  align-items: center;
  display: flex;
  justify-content: center;
  height: 100%;
  width: 100%;
}
.box {
  border-radius: 5px;
  font-family: sans-serif;
  text-align: center;
  max-width: 50%;
  max-height: 50%;
  padding: 20px 40px;
}

HTML