<svg viewBox="0 0 100 1000">
  <path stroke="#444" fill="none" stroke-width="2" d="M50,0 C100,0 100,50 50,50
    C0,50 0,100 50,100
    C100,100 100,150 50,150
    C0,150 0,200 50,200
    C100,200 100,250 50,250
    C0,250 0,300 50,300
    C100,300 100,350 50,350
    C0,350 0,400 50,400
    C100,400 100,450 50,450
    C0,450 0,500 50,500
    C100,500 100,550 50,550
    C0,550 0,600 50,600
    C100,600 100,650 50,650
    C0,650 0,700 50,700
    C100,700 100,750 50,750
    C0,750 0,800 50,800
    C100,800 100,850 50,850
    C0,850 0,900 50,900
    C100,900 100,950 50,950
    C0,950 0,1000 50,1000
    C100,1000 100,1050 50,1050" id="theMotionPath" />
  <circle cx="" cy="" r="15" fill="#45bcde" id="css-motion-path"/>
  <circle cx="" cy="" r="15" fill="red">

          <!-- Define the motion path animation -->
          <animateMotion dur="5s" repeatCount="indefinite">
             <mpath xlink:href="#theMotionPath"/>
          </animateMotion>
      </circle>
</svg>
<aside>
<p>
  This is an SVG with a curvy path, a red circle, and a blue circle. The red circle is animated with SMIL. The blue circle is animated with CSS Motion Path + CSS Animations. 
  </p>
  <p>SMIL defines an <code>animateMotion</code> inside the circle element in the SVG. It has good support in Chrome, Firefox, Opera, &amp; Safari... though it is deprecated in Chrome/Opera (not to happen any time soon, however, as alternatives need to be fully implemented before that happens). There is currently no Edge support.
  <p>CSS Motion Path has pieces implemented in Chrome (46+) &amp; Opera (33+) through the <code>motion</code> properties (<code>motion-path</code> + <code>motion-offset</code>). This is an early spec and the properties have been renamed, so Chrome 56+ supports this through the equivalent but renamed <code>offset</code> properties (<code>offset-path</code> + <code>offset-distance</code>).
</p>
</aside>

svg {
  height: 1000px;
  width: 100px;
}
svg circle#css-motion-path {
  animation: move-it 5s -2.5s infinite both linear;
  motion-path: path("M50,0 C100,0 100,50 50,50 C0,50 0,100 50,100 C100,100 100,150 50,150 C0,150 0,200 50,200 C100,200 100,250 50,250C0,250 0,300 50,300C100,300 100,350 50,350C0,350 0,400 50,400C100,400 100,450 50,450C0,450 0,500 50,500C100,500 100,550 50,550C0,550 0,600 50,600  C100,600 100,650 50,650    C0,650 0,700 50,700    C100,700 100,750 50,750    C0,750 0,800 50,800    C100,800 100,850 50,850    C0,850 0,900 50,900    C100,900 100,950 50,950    C0,950 0,1000 50,1000    C100,1000 100,1050 50,1050");
  offset-path: path("M50,0 C100,0 100,50 50,50 C0,50 0,100 50,100 C100,100 100,150 50,150 C0,150 0,200 50,200 C100,200 100,250 50,250C0,250 0,300 50,300C100,300 100,350 50,350C0,350 0,400 50,400C100,400 100,450 50,450C0,450 0,500 50,500C100,500 100,550 50,550C0,550 0,600 50,600  C100,600 100,650 50,650    C0,650 0,700 50,700    C100,700 100,750 50,750    C0,750 0,800 50,800    C100,800 100,850 50,850    C0,850 0,900 50,900    C100,900 100,950 50,950    C0,950 0,1000 50,1000    C100,1000 100,1050 50,1050");
}

@keyframes move-it {
  100% {
    motion-offset: 100%;
    offset-distance: 100%;
  }
}

aside {
  display: inline-block;
  color: #d4d7dd;
  font-size: 1.2rem;
  font-size: calc(3vw + .2em);
  line-height: 1.4;
  font-family: -apple-system, "Segoe UI", "Roboto", sans-serif;
  padding: 2rem;
  width: calc(100% - 100px);
}
p {
  margin-bottom: 2rem;
}
code {
  font-family: monospace;
}

body {
  height: 100vh;
  background: #16161c;
  display: flex;
}
* {
  box-sizing: border-box;
}