For teams searching the older Interactive Avatar name, HeyGen’s current LiveAvatar documentation is the first migration path to assess. Spatius is the strongest architectural alternative for client rendering, while Tavus, Anam, and Simli cover managed CVI, turnkey persona, and focused voice-bot use cases.
Why the old product name still matters.
Existing code, tutorials, and internal documents can outlive a product generation.
Teams searching “HeyGen Interactive Avatar alternatives” are often not starting from a blank page. They may operate code written against an earlier SDK, depend on specific session events, or have prototypes built around HeyGen avatar IDs and a browser video stream. LiveAvatar’s current documentation includes a migration guide from HeyGen Interactive Avatar and describes FULL and LITE modes, a Web SDK, embed flow, and custom real-time transport options. That makes current LiveAvatar the continuity candidate. It does not automatically make it the best future architecture. A migration window is a useful time to reconsider where rendering occurs, which AI components remain replaceable, which clients must be supported, and how session economics behave at production volume.
Choose continuity or redesign.
The first option minimizes conceptual change; the others change the product boundary.
1. LiveAvatar
LiveAvatar is HeyGen’s current real-time avatar product and its official documentation includes a migration guide for Interactive Avatar users. FULL mode handles the complete AI pipeline, while LITE mode lets developers provide the conversational stack. Start here when preserving the cloud-video approach and vendor relationship is more important than changing architecture.
2. Spatius
Spatius replaces continuous cloud-video delivery with motion data and client rendering. It expects the application to own ASR, LLM, TTS, tools, and logic. Choose this path when the migration is an opportunity to separate the avatar from the agent and deliver through published Web, iOS, and Android SDKs.
3. Tavus
Tavus combines a persona, replica, and managed real-time conversation. Its official API overview describes an end-to-end CVI for a replica that can see, hear, and respond. Consider it when the replacement should own more perception and conversation infrastructure than the older Interactive Avatar integration did.
4. Anam
Anam’s persona model combines a face, voice, LLM, and system prompt. Turnkey mode manages all four stages of the conversational pipeline, while documented configurations accept customer components. It fits a web-first rebuild centered on persona configuration rather than compatibility with old session objects.
5. Simli
Simli exposes JavaScript and Python SDKs intended to connect interactive avatars to an existing AI stack. This path is useful when the legacy code already has turn-taking, an LLM, voice, and tools and the migration should replace only the visual speech layer.
HeyGen Studio is a different job
HeyGen’s asynchronous video-creation product should be evaluated separately from a real-time avatar session. If the actual requirement has shifted to scripted marketing, training, localization, or presentation video, compare video editors and generation workflows rather than forcing a live-avatar API into the shortlist.
Estimate how much must change.
“Effort” is directional; confirm it against your current code and requirements.
| Path | Product continuity | Rendering approach | Conversation ownership | Migration focus |
|---|---|---|---|---|
| LiveAvatar | Highest conceptual continuity | Cloud-rendered live video | FULL or LITE mode | Map old SDK calls and lifecycle to current APIs |
| Spatius | Architecture changes materially | Client rendering from motion data | Customer-owned AI stack | Integrate AvatarKit and preserve the voice agent |
| Tavus | New managed CVI | Managed conversational video | End-to-end pipeline available | Rebuild persona, replica, and room flow |
| Anam | New persona platform | Cloud face-generation stream | Turnkey or selected custom parts | Recreate face, voice, prompt, and tools |
| Simli | New visual layer | Real-time speech-to-video | Customer connects the agent stack | Replace avatar transport and UI events |
Pick a migration strategy, not just a vendor.
Compatibility and future fit are separate scores.
Prefer continuity when…
- The current cloud-video experience already meets product and network goals.
- The team cannot absorb a major architectural rewrite this release.
- Current LiveAvatar modes cover the required AI-stack ownership.
- The official migration path preserves custom avatars, UI behavior, and commercial terms.
Use the migration to redesign when…
- Native mobile or client-rendered delivery is now essential.
- The product already has a mature voice agent and wants a narrow avatar layer.
- Visual perception or a broader managed CVI is a new requirement.
- Legacy session cost, concurrency, transport, or lifecycle assumptions no longer scale.
Build a compatibility map before touching production.
Export current behavior into a test contract. The goal is to find breaking differences while both systems can still run side by side.
- Record a golden ten-turn session from the legacy implementation, including one interruption and reconnect.
- Replay the same inputs against current LiveAvatar and two architecture alternatives.
- Run old and new clients behind a feature flag with isolated analytics and rollback.
- Verify visual identity and consent assets can legally and technically move to the new system.
- Cut over only after session completion, error rate, latency, network use, and cost meet written acceptance thresholds.
Official migration and product sources.
Last reviewed Aug 3, 2026. Use the current vendor docs during implementation.