CSS

how to blur background color in css

background: rgba(255,255,255,0.5);
backdrop-filter: blur(5px);

how to do a background blur in css

/* Answer to "blur behind element css" */

/*
	This blurs everything behind the element it's applied to
*/

backdrop-filter: blur(10px);

how to blur background image in css

/* Setting background image and filter to blur */
body{
      background-image: url("software_code_3.jpg");
      background-position: center;
      background-repeat: no-repeat;
      background-size: cover;
      background-attachment: fixed;
      color: whitesmoke;
      backdrop-filter: blur(8px);
/*       -webkit-filter: blur(8px); */
    }
/* creating a kind of "glass-polymorphism" effect with a light-dark background*/
.container {
      border: 1px;
      border-radius: 5px;
      background-color: rgb(0,0,0);
      background-color: rgba(0,0,0, 0.4);
      padding: 20px;
    }

background blur css

background: transparent;
backdrop-filter: blur(10px);

blur css

.mydiv { filter: grayscale(50%) }

/* Graut alle Bilder um 50% aus und macht sie um 10px unscharf */
img {
  filter: grayscale(0.5) blur(10px);
}

add blur background css

backdrop-filter: blur(5px);

blur css

backdrop-filter: blur(6px);

blur background image css

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

.container {
  width: 100%;
  height: 100%;
  
  display: grid;
  grid-template-columns: 1fr 6fr 1fr;
  grid-template-rows: 1fr 6fr 1fr;
  grid-template-areas: 
  '. . .'
  '. content .'
  '. . .'; 
  justify-content: center;
  align-items: center;
}

.backbround {
  width: 100%;
  height: 100%;
  
  grid-area: 1/1/5/5;
  
  background-image: url(https://i.imgur.com/aUhpEz3.jpg);
  filter: blur(5px);
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

.content {
  height: 200px;
  position: relative;
  
  grid-area: content;
  display: flex;
  
  justify-content: center;
  align-items: center;
  color: white;
}