HeyGen modelsvideo generation api

heygen/heygen/lipsync/precision

Name: HeyGen Lipsync Precision
Author: HeyGen

Heygen Lipsync Precision by HeyGen - AI-powered video editing and transformation. Apply style transfer, motion control, lip-sync, and visual effects to existing videos with natural language instructions.

Input

Video Url(string)

URL of the source video to lip-sync.

Audio Url(string)

URL of the replacement audio file.

Idle

Example output — click Run to generate your own

Production endpoint

Send your first request

OpenAI-compatible endpoint with unified authentication and usage tracking.

POSThttps://api.sandbase.ai/v1/run

Model IDheygen/heygen/lipsync/precision

Input Schema

2 parameters · 0 required · 2 optional

Parameter	Type	Required	Description
`audio`	string	Optional	URL of the replacement audio file.
`video`	string	Optional	URL of the source video to lip-sync.

Output Schema

Field	Type	Description
`id`	string	Unique identifier for the generation task
`status`	string	Task status: pending, running, completed, failed, timeout
`model`	string	Model used for the generation
`outputs`	array	Array of output items
`outputs[].url`	string	URL of the generated artifact
`outputs[].content_type`	string	MIME type (e.g. image/png, video/mp4)
`error`	object \| null	Error details if failed, null on success
`error.type`	string	Machine-readable error type code
`error.message`	string	Human-readable error description

Async Workflow

This model uses asynchronous execution. Submit a request and poll for the result.

Submit — POST to /v1/run, receive an id
Poll — GET /v1/run/{id} until status is completed, failed, or timeout
Retrieve — Read outputs from the completed response

Code Examples

Ready-to-run snippets

# Step 1: Submit
curl -X POST https://api.sandbase.ai/v1/run \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
  "model": "heygen/heygen/lipsync/precision",
  "audio": "https://static.sandbase.ai/examples/mirelo/sfx1.6/inpaint-audio/output_url_0.wav",
  "video": "https://static.sandbase.ai/examples/heygen/heygen/lipsync/precision/input_video_0.mp4",
  "prompt": "a beautiful sunset over mountains"
}'

# Step 2: Poll result (replace <id>)
curl https://api.sandbase.ai/v1/run/<id> \
  -H "Authorization: Bearer YOUR_API_KEY"

← Back to HeyGen Lipsync Precision

API README

HeyGen Lipsync Precision

heygen/heygen/lipsync/precision retimes visible mouth movement in existing footage to match replacement speech while prioritizing visual accuracy. Precision mode spends more processing effort on phoneme alignment, mouth shape, and challenging facial motion for polished dubbing. This combination makes the model a practical choice when the creative outcome depends on those qualities rather than on a generic media conversion.

For production work with heygen/heygen/lipsync/precision, it is intended for final localization and dialogue replacement when tighter audiovisual alignment matters more than the fastest turnaround. The result is most reliable when the source material and creative brief clearly describe the intended subject, progression, visual or sonic character, and the qualities that must remain unchanged.

Highlights

Precise phoneme alignment matches visible mouth shapes closely to replacement speech.

Performance preservation keeps the source actor's expression, pose, and scene intact.

Dubbing realism integrates a new spoken track without reshooting the original footage.

Challenging-shot handling improves synchronization across varied angles and facial motion.

Pricing

Generated or processed duration	Price
Per second	$0.100

When to Use

✅ Good fit	❌ Consider alternatives
The model's named workflow matches the source material and intended output	A different input modality or model route is required
A managed asynchronous result is suitable for the production pipeline	A synchronous, interactive editor is essential
The documented controls cover the required duration, framing, or format	The project needs controls outside this endpoint's schema
Creative iteration benefits from a repeatable request structure	Exact deterministic pixels, frames, geometry, or samples are mandatory
A finished downloadable media asset is the desired deliverable	Editable source layers or a native project file are required

Prompt Guide

For audio transformation, state the intended result first, then add the subject or source treatment, progression, style, and delivery constraints. Keep one creative variable per phrase, use the documented field names for controls, and change one setting at a time when comparing results.

{
  "audio": "https://static.sandbase.ai/examples/mirelo/sfx1.6/inpaint-audio/output_url_0.wav",
  "video": "https://static.sandbase.ai/examples/heygen/heygen/lipsync/precision/input_video_0.mp4"
}

Technical Specs

Spec	Value
Model ID	`heygen/heygen/lipsync/precision`
Inputs	audio, video
Required inputs	None
Output fields	content_type, url
Execution	Async (submit, then poll for result)