Flexible and efficient solution

Airbnb is a global company that supports millions of guests and hosts, so having a flexible animation format that is playable on multiple platforms was extremely important to us. There are libraries similar to Lottie, such as Marcus Eckert’s Squall and Facebook’s Keyframes, but our goals are slightly different. Facebook picked a small set of After Effects features to support, since they were focusing mainly on reactions, but we want to support as many as possible. As for Squall, designers at Airbnb use it in combination with Lottie because it has an amazing After Effects preview app that’s become a necessary part of our workflow. However, it only supports iOS and our engineering teams needed a cross-platform solution.

Lottie also has several features built into its API to make it more versatile and efficient. It supports loading JSON files over the network, which is useful for A/B testing. It also has an optional caching mechanism, so frequently used animations, such as a wish-list heart, can load a cached copy each time. Lottie animations can be driven by gestures using the animated progress feature, and animation speed can be manipulated by changing a simple value. iOS even supports adding additional native UI to an animation at runtime, which can be used for complex animated transitions.

In addition to all of the After Effects features and API additions we’ve worked on so far, we have many ideas for the future. These include mapping views to Lottie animations, controlling view transitions with Lottie, support for Battle Axe’s RubberHose, gradient, type, and image support. The hardest part is picking which features to tackle next.