This example uses OpenLayers v10.9.0. The latest is v.
Edit

#### Custom Animation

animation 5 vector 86 feature 12 flash 1

#####

Demonstrates how to animate features.

This example shows how to use postrender and vectorContext to animate features. Here we choose to do a flash animation each time a feature is added to the layer.

##### main.js

    import Feature from 'ol/Feature.js';
    import Map from 'ol/Map.js';
    import {unByKey} from 'ol/Observable.js';
    import View from 'ol/View.js';
    import {easeOut} from 'ol/easing.js';
    import Point from 'ol/geom/Point.js';
    import TileLayer from 'ol/layer/Tile.js';
    import VectorLayer from 'ol/layer/Vector.js';
    import {fromLonLat} from 'ol/proj.js';
    import {getVectorContext} from 'ol/render.js';
    import OSM from 'ol/source/OSM.js';
    import VectorSource from 'ol/source/Vector.js';
    import CircleStyle from 'ol/style/Circle.js';
    import Stroke from 'ol/style/Stroke.js';
    import Style from 'ol/style/Style.js';

    const tileLayer = new TileLayer({
      source: new OSM({
        wrapX: false,
      }),
    });

    const source = new VectorSource({
      wrapX: false,
    });
    const vector = new VectorLayer({
      source: source,
    });

    const map = new Map({
      layers: [tileLayer, vector],
      target: 'map',
      view: new View({
        center: [0, 0],
        zoom: 1,
        multiWorld: true,
      }),
    });

    function addRandomFeature() {
      const x = Math.random() * 360 - 180;
      const y = Math.random() * 170 - 85;
      const geom = new Point(fromLonLat([x, y]));
      const feature = new Feature(geom);
      source.addFeature(feature);
    }

    const duration = 3000;
    function flash(feature) {
      const start = Date.now();
      const flashGeom = feature.getGeometry().clone();
      const listenerKey = tileLayer.on('postrender', animate);

      function animate(event) {
        const frameState = event.frameState;
        const elapsed = frameState.time - start;
        if (elapsed >= duration) {
          unByKey(listenerKey);
          return;
        }
        const vectorContext = getVectorContext(event);
        const elapsedRatio = elapsed / duration;
        // radius will be 5 at start and 30 at end.
        const radius = easeOut(elapsedRatio) * 25 + 5;
        const opacity = easeOut(1 - elapsedRatio);

        const style = new Style({
          image: new CircleStyle({
            radius: radius,
            stroke: new Stroke({
              color: 'rgba(255, 0, 0, ' + opacity + ')',
              width: 0.25 + opacity,
            }),
          }),
        });

        vectorContext.setStyle(style);
        vectorContext.drawGeometry(flashGeom);
        // tell OpenLayers to continue postrender animation
        map.render();
      }
    }

    source.on('addfeature', function (e) {
      flash(e.feature);
    });

    window.setInterval(addRandomFeature, 1000);

##### index.html

    <!DOCTYPE html>
    <html lang="en">
      <head>
        <meta charset="UTF-8">
        <title>Custom Animation</title>
        <link rel="stylesheet" href="node_modules/ol/ol.css">
        <style>
          .map {
            width: 100%;
            height: 400px;
          }
        </style>
      </head>
      <body>
        <div id="map" class="map"></div>

        <script type="module" src="main.js"></script>
      </body>
    </html>

##### package.json

    {
      "name": "feature-animation",
      "dependencies": {
        "ol": "10.9.0"
      },
      "devDependencies": {
        "vite": "^3.2.3"
      },
      "scripts": {
        "start": "vite",
        "build": "vite build"
      }
    }