Lottie is described as 'Render After Effects animations natively on Web, Android and iOS, and React Native' and is an app in the Development category. There are four alternatives to Lottie for Online / Web-based and Self-Hosted solutions. The best alternative is Animator. It's not free, so if you're looking for a free alternative, you could try Keyframes or LottieLab.
Animator by Haiku is a creative environment for crafting codebase-ready animations. Carefully built around modern workflows, Animator integrates with your favorite design and code tools, and it's all backed by git version
Create and edit Lottie animations. Built for Lottie from the ground up. Create and edit animations, no plugins needed. For Developers Edit illustrations and micro-interactions without needing to disturb a designer.