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LATENTSYNC

A video-to-video model, LatentSync generates accurate lip sync from audio for natural, high-quality results

Avg Run Time: 45.000s

Model Slug: latentsync

Playground

Input

Enter a URL or choose a file from your computer.

Enter a URL or choose a file from your computer.

Output

Example Result

Preview and download your result.

Flat $0.20 up to 40s, then $0.005 per second overage from output duration

API & SDK

Create a Prediction

Send a POST request to create a new prediction. This will return a prediction ID that you'll use to check the result. The request should include your model inputs and API key.

Get Prediction Result

Poll the prediction endpoint with the prediction ID until the result is ready. The API uses long-polling, so you'll need to repeatedly check until you receive a success status.

Readme

Table of Contents
Overview
Technical Specifications
Key Considerations
Tips & Tricks
Capabilities
What Can I Use It For?
Things to Be Aware Of
Limitations

Overview

latentsync — Video-to-Video AI Model

latentsync, developed by Alibaba as part of the latentsync family, delivers precise lip synchronization for video-to-video generation, transforming input videos and audio into natural, high-fidelity outputs with accurate facial movements. This Alibaba video-to-video model excels at creating realistic lip sync from audio inputs, solving the challenge of mismatched mouth movements in AI-generated talking head videos. Users searching for video-to-video AI model with superior audio-visual alignment find latentsync ideal for professional-grade results without manual editing.

Built on advanced diffusion technology, latentsync supports seamless integration of audio-driven expressions, making it a go-to for creators needing Alibaba latentsync API capabilities in dynamic video production.

Technical Specifications

What Sets latentsync Apart

latentsync stands out in the competitive landscape of video-to-video AI models through its high-precision lip sync technology based on diffusion models, enabling frame-accurate mouth movements that match audio phonemes exactly. This allows content creators to produce broadcast-ready videos where characters speak naturally, even with complex dialogue or accents, outperforming generic models in sync fidelity.

Unlike standard video-to-video tools, latentsync handles multi-format inputs including real people, cartoons, and digital humans while maintaining identity consistency and cinematic-quality expressions. Developers using the latentsync API benefit from this versatility, generating portrait, half-body, or full-body videos with enhanced motion control via text instructions.

Key technical specifications include support for resolutions up to 768x512 or multiples of 32 (recommended not exceeding 720x1280), frame counts like 65 frames (~2.5 seconds at 25 FPS), and frame rates that are multiples of 8+1. Processing leverages efficient samplers with 10-25 steps for fast, high-quality renders, ideal for Alibaba video-to-video workflows in ComfyUI environments.

  • Audio-driven precision: Achieves natural lip-sync and expressions from clean vocal tracks, superior for dialogue-heavy content.
  • Extended generation: Supports minute-level videos through chained extensions, with metrics like CSIM 0.677 for strong identity preservation.
  • Motion control: Uses AdaIN and CrossAttention for text-guided actions, differentiating it from basic frame interpolation models.

Key Considerations

  • Clean, isolated vocal tracks yield the best lip sync results; background noise or music can degrade accuracy
  • Proper alignment of audio and video input is crucial for optimal synchronization
  • For long videos, ensure sufficient computational resources to maintain quality and temporal consistency
  • Using high-quality reference frames improves facial realism and identity preservation
  • There is a trade-off between generation speed and output quality; lower step counts accelerate inference but may reduce fidelity
  • Batch processing and chunking strategies can help manage memory usage for extended video sequences
  • Prompt engineering (e.g., specifying desired expressions or speaking styles) can enhance expressiveness and realism

Tips & Tricks

How to Use latentsync on Eachlabs

Access latentsync through Eachlabs Playground for instant testing—upload a source video via VHS_LoadVideo node, add audio track, set resolution (e.g., 768x512), frame count (up to 257), and CFG (2-4 for video-to-video). Integrate via Eachlabs API or SDK with parameters like prompts, sigma_shift for motion tuning, and samplers (Euler, 10-20 steps) to output MP4 videos in high quality. Get natural lip sync results in seconds to minutes depending on length.

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Capabilities

  • Generates highly accurate and natural lip synchronization from audio for video subjects
  • Maintains strong temporal consistency across frames, reducing jitter and unnatural transitions
  • Supports high-resolution video output with detailed facial expressions and mouth movements
  • Adapts to various input formats and is robust to different speaker identities and languages
  • Excels at handling complex audio-visual correlations, producing expressive and realistic results
  • Suitable for both short clips and longer video sequences without significant loss of quality

What Can I Use It For?

Use Cases for latentsync

Content creators producing YouTube explainer videos can input a talking head clip and spokesperson audio, using latentsync to generate perfectly synced lip movements across diverse styles like cartoons or real humans, saving hours on post-production dubbing.

Marketers developing promotional content for e-commerce benefit from latentsync's ability to animate product demo videos with voiceover sync; for instance, feed a static image of a model holding a gadget plus audio saying "Discover our latest smartwatch with heart rate tracking," and receive a fluid video showcasing natural expressions and gestures.

Developers integrating video-to-video AI model APIs into apps for virtual avatars use latentsync's multi-resolution support (512x512 to 1024x1024) and long-form extension, enabling scalable deployment for customer service bots with realistic lip-synced responses.

Filmmakers experimenting with dubbing foreign films leverage its high-fidelity audio processing, separating vocals for clean inputs that yield cinematic-grade outputs with authentic facial dynamics, perfect for international distribution workflows.

Things to Be Aware Of

  • Some users report that background noise or music in the audio input can cause lip sync inaccuracies or artifacts
  • The model requires substantial computational resources, especially for high-resolution or long-duration videos
  • Temporal consistency is significantly improved over previous diffusion-based methods, but may still show minor artifacts in challenging scenarios
  • Users highlight the importance of clean reference frames for maintaining identity and realism
  • Positive feedback centers on the model’s naturalness, expressiveness, and adaptability to various use cases
  • Negative feedback occasionally mentions longer processing times for high-quality outputs and the need for careful audio preprocessing
  • Experimental features, such as advanced temporal alignment settings, may require tuning for optimal results

Limitations

  • High computational and memory requirements may limit accessibility for users without powerful hardware
  • Performance may degrade with poor-quality audio or non-speech inputs, resulting in less accurate lip sync
  • Not optimal for real-time applications or scenarios requiring ultra-fast inference

Pricing

Pricing Type: Dynamic

Flat $0.20 up to 40s, then $0.005 per second overage from output duration

FREQUENTLY ASKED QUESTIONS

Dev questions, real answers.

LatentSync is an AI lipsync model by Alibaba that synchronizes the lip movements of a person in a video to a provided audio track. Using latent diffusion techniques, it produces accurate, temporally consistent lip sync with natural facial dynamics, suitable for dubbing and voice replacement workflows.

LatentSync is available through the eachlabs unified API. Submit a source video and a target audio file; the model returns a video with updated lip movements synchronized to the new audio. Billing is pay-as-you-go through eachlabs.

LatentSync is best suited for video dubbing, AI avatar voiceover replacement, and multilingual video localization. Its diffusion-based approach produces high visual quality lipsync that maintains natural skin texture and motion consistency, making it suitable for professional video production workflows.