Hy4 preview vs LongCat Video Avatar: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of Hy4 preview and LongCat Video Avatar — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
Hy4 preview
Tencent
Tencent's open-weight Hy4 preview, a 770B-parameter Mixture-of-Experts model with 49B active parameters and a 1M-token context window.
Key features
- 770B Mixture-of-Experts Architecture: Holds 770 billion total parameters while activating only 49 billion per token, so capacity scales without proportional inference cost.
- 1M-Token Context Window: Accepts inputs exceeding one million tokens, allowing whole codebases, long document sets or extended agent traces in a single prompt.
- Apache 2.0 Open Weights: Released under a permissive licence that allows commercial use, modification and redistribution with no separate agreement.
- Productivity Task Focus: Tuned for real-world coding, office work and scientific research rather than narrow benchmark optimisation.
- Multi-Product Availability: Accessible globally through Tencent's WorkBuddy, CodeBuddy, Yuanbao and ima applications in addition to the raw weights.
- API Access via TokenHub and OpenRouter: Can be called through Tencent Cloud TokenHub or OpenRouter for teams that prefer hosted inference over self-hosting.
Best for
- Whole-Repository Code Work: Load an entire codebase into the million-token context to reason about refactors and cross-file dependencies at once.
- Long-Horizon Agent Tasks: Drive multi-step agent workflows where the full history of tool calls and intermediate results must stay in context.
- Self-Hosted Deployment: Run a frontier-scale open-weight model on private infrastructure where data cannot leave the organisation.
- Scientific Literature Analysis: Ingest large collections of papers or experimental logs and synthesise findings without chunking the input.
- Office Document Processing: Summarise, draft and restructure long reports, contracts and spreadsheets in enterprise workflows.
- Commercial Fine-Tuning: Adapt the weights for a proprietary product under the Apache 2.0 licence without negotiating a model licence.
LongCat Video Avatar
LongCat Avatar
Generates ultra-realistic, audio-driven, lip-synced long avatar videos with stable identity, natural motion, multi-person support, and video continuation.
Key features
- Audio-Driven Generation: Converts input audio tracks into synchronized avatar video, allowing voice-driven creation of full-length speaking performances.
- Ultra-Realistic Lip-Sync: Produces precise mouth and jaw movements aligned to phonetic timing for natural, believable speech animation.
- Stable Identity Preservation: Maintains consistent facial features, skin tone, and appearance across long videos and extended continuations to prevent drift.
- Natural Motion and Expression: Generates head movements, eye motion, gestures, and micro-expressions to enhance realism and reduce synthetic stiffness.
- Multi-Person Support: Creates scenes containing multiple distinct avatars, each with independent identity preservation and accurate lip-sync to separate audio sources.
- Video Continuation & Extension: Seamlessly continues or lengthens existing footage while preserving motion patterns and identity, enabling long-form video production.
- Audio-driven avatar video synthesis (generates video from audio input)
- High-quality lip synchronization between audio and mouth movements
- Stable identity preservation across long video durations
- Natural, realistic motion and expression generation
- Multi-person avatar generation and support
- Video continuation/extension capabilities for longer outputs
Best for
- Long-Form Content Creation: Convert lectures, webinars, and podcasts into continuous, lip-synced avatar videos for on-demand viewing.
- Virtual Presenters and E-Learning: Produce consistent presenter avatars for training courses, corporate communications, and educational modules.
- Dubbing and Localization: Replace or translate audio tracks and regenerate lip-synced avatar video for different languages and regions.
- Multi-Character Storytelling: Create multi-person scenes for short films, animations, or social media content with distinct, synchronized avatars.
- Customer-Facing Virtual Agents: Generate standardized agent videos for support, onboarding, and FAQ walkthroughs with stable identity over time.
- Social Media and Brand Avatars: Produce regular branded video content using consistent influencer-style avatars to maintain recognizability.
- Creating long-form avatar-led content from recorded audio (podcasts, narrations)
- Virtual presenters and spokesperson videos with stable identity
- Multi-person virtual interviews or panel simulations
- Dubbing or revoicing video content with synchronized avatar visuals
- Content continuation or extension where existing avatar videos are extended seamlessly