Lottie is the industry default for shipping designer-made motion to the web. Glim is a companion library built around a four-state AI mind. They overlap in “something should move,” but they solve different jobs.
Quick comparison
| Dimension | Glim | Lottie |
|---|---|---|
| Core job | Readable AI presence (idle/thinking/talking/listening) | Play vector animations from After Effects / tools |
| State model | Built-in four-state mind + themes | You invent state → animation mapping |
| Authoring | Pick a creature + API | Design / export JSON, then integrate |
| Dependencies | Zero (single glim.js) | Player runtime + asset files |
| Best for | AI latency, copilots, agent UIs | Brand motion, onboarding, empty states |
When Lottie is the right call
- You already have a motion design system in After Effects or similar.
- The animation is a one-shot delight (success confetti, empty-state illustration).
- Brand marketing needs pixel-perfect designer control frame by frame.
Lottie is excellent at performance of a designed clip. It is not opinionated about what “thinking” means in your product.
When Glim is the right call
- You need a continuous presence that changes with model lifecycle.
- You want a shared vocabulary across creatures without re-exporting JSON for every mood.
- You care about a free offline starter and a tiny runtime for product UI, not marketing pages alone.
Glim’s API is deliberately small: mount, setState, say, react, setTheme, destroy. That is the surface area AI product builders actually wire to streams and tool calls.
Can you use both?
Yes. A common pattern:
- Glim for the always-on companion beside chat or an agent panel.
- Lottie for rare ceremonial moments (first success, plan complete).
Do not stack both in the same 40×40 corner. One composition, one job.
Bottom line
Choose Lottie when the artifact is an animation file. Choose Glim when the artifact is a mind users can read while the model works. For AI products, the mind usually matters more than the clip.
Try Glim free. Offline starter + MIT creatures. No fake checkout.