Lottie is an open format for animated vector graphics

Original Article ↗ Hacker News Discussion ↗

Use cases and strengths

  • Seen as a useful bridge between motion designers (esp. After Effects users) and developers: export once, reuse in web, mobile, games, and video pipelines.
  • Well-suited for complex, cartoon‑like animations and branded flourishes (e.g., app intro/empty states, Telegram-style stickers, PBS KIDS branding, transparent icon‑like videos).
  • Runtime-editable text is valued on mobile for localization without shipping many separate assets.
  • Some organizations report smooth workflows: AE → Lottie JSON → MOV/SVG variants for different platforms.

File format, size, and performance concerns

  • Heavy criticism of the JSON-based format: verbose numeric data, base64-embedded assets, external file references, and .lottie ZIPs that require multiple parsing steps.
  • Lottie JS/web runtimes can be very large (hundreds of KB to multiple MB), often dominating bundle size for relatively small UI animations.
  • Users report high CPU usage and poor scalability when many animations run simultaneously, especially on low-end devices.
  • For small microinteractions (icons, spinners), many see Lottie as overkill versus CSS/SVG, WebM/VP9/AV1, or animated WebP.
  • Some argue zipped JSON is an acceptable compromise; others push for compact binary formats (e.g., Protobuf/CBOR) and zero‑copy designs.

Workflow and authoring experience

  • AE → Lottie export is described as fragile: most AE features are unsupported; designers must stay within undocumented limits with little in‑tool feedback.
  • Maintaining complex dynamic animations requires brittle layer‑name conventions and auxiliary libraries; collaboration cycles between design and engineering can be painful.
  • Complaints about difficulty of server‑side rendering initial frames, though workarounds (static first frame, progressive enhancement) exist.

Comparison with CSS/SVG and Flash

  • Many argue most UI animations are better done with CSS/Web Animations + SVG: smaller, more direct, and often hardware accelerated.
  • Others counter that Lottie’s value is precisely in handling the rich, AE‑level cases nobody wants to code by hand.
  • Long subthread compares Lottie/web standards to Flash: nostalgia for Flash’s simple, powerful authoring environment versus acknowledgment of its security, energy, and accessibility problems.
  • Some see current web animation stacks as fragmented and unfriendly to non‑technical creatives, and call for a new, open, binary animation standard plus a Flash‑like editor.

Alternatives and ecosystem

  • Rive is frequently praised: lighter, better editor, open‑source format and runtimes, and more suitable for dynamic data, though some report performance and UX quirks.
  • Other tools mentioned: SVGator, Tumult Hype, Google Web Designer, Expressive Animator, Glaxnimate, Lottielab (good editor but large outputs and paid compression).
  • Native libraries: Samsung’s rlottie (warned as insecure with untrusted input), and ThorVG as a more robust, portable Lottie-capable engine.
  • Airbnb’s newer Lava format (micro‑videos) is used in some places instead of Lottie, but targets different use cases; overall level of ongoing Lottie investment is unclear.