Instead of a CSS-animated spinner, Slack uses a Lottie animation of its logo bouncing and wiggling. The JSON file is 12KB vs a 300KB GIF.
To ensure fidelity, designers must convert text to shapes before export. This destroys editability and increases file size exponentially (each letter becomes a set of paths). Editable text requires embedding custom fonts, which is legally and technically complex.
Bodymovin: Revolutionizing Motion Design Workflows through JSON-Based Rendered Animation bodymovin plugin after effects
"v": "5.9.6", // Version "fr": 30, // Frame rate "w": 500, // Width "h": 500, // Height "layers": [...], // Array of layer objects "assets": [...], // Images or pre-comps "layers[0].shapes[0].it": // Shape path data "ty": "sh", "ks": "k": [ "i": [...], "o": [...], "v": [...] ]
Linear and radial gradients in After Effects often render with different color stops or angles in Lottie-iOS vs. Lottie-web due to differing interpretation of gradient matrices. Instead of a CSS-animated spinner, Slack uses a
import lottie from 'lottie-web'; const animation = lottie.loadAnimation( container: document.getElementById('anim-container'), renderer: 'svg', // 'svg', 'canvas', or 'html' loop: true, autoplay: true, path: 'data.json' );
Journalistic features use Bodymovin exported animations triggered by scroll events (using Lottie-interactivity). Charts and diagrams animate as the user scrolls, syncing precisely to scroll percentage. 8. Limitations and Criticisms 8.1 The "Matrix of Pain" The lack of expression support is the most common designer complaint. In After Effects, a designer might use time*360 to rotate a wheel infinitely. Bodymovin will ignore this, requiring the designer to create a 1-second loop cycle or use the Lottie API to manually drive rotation. Bodymovin will ignore this
// Runtime control animation.play(); animation.setSpeed(0.5); animation.goToAndStop(60, true); A critical understanding for motion designers is that Bodymovin does not support 100% of After Effects .