.pulse-box {
  float: left;
  width: 50%;
  height: 250px;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* pulse in SVG */
svg.pulse-svg {
  overflow: visible;
}
svg.pulse-svg .first-circle, svg.pulse-svg .third-circle, svg.pulse-svg .second-circle {
  fill: #f00;
  transform: scale(0.5);
  transform-origin: center center;
  animation: pulse-me 3s linear infinite;
}
svg.pulse-svg .second-circle {
  animation-delay: 1s;
}
svg.pulse-svg .third-circle {
  animation-delay: 2s;
}

/* pulse in CSS */
.pulse-css {
  width: 50px;
  height: 50px;
  border-radius: 25px;
  background: tomato;
  position: relative;
}
.pulse-css:before, .pulse-css:after {
  content: "";
  width: 50px;
  height: 50px;
  border-radius: 25px;
  background-color: tomato;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
  transform: scale(0.5);
  transform-origin: center center;
  animation: pulse-me 3s linear infinite;
}
.pulse-css:after {
  animation-delay: 2s;
}

@keyframes pulse-me {
  0% {
    transform: scale(0.5);
    opacity: 0;
  }
  50% {
    opacity: 0.1;
  }
  70% {
    opacity: 0.09;
  }
  100% {
    transform: scale(5);
    opacity: 0;
  }
}