HeyGen Avatar IV
HeyGen Avatar IV is a photorealistic AI avatar generation model that creates talking videos from a single image and a script or audio input. The model synchronizes voice with facial motion, expressions, and gestures to produce lifelike avatar performances. It supports multilingual speech, realistic lip synchronization, and expressive body language, enabling scalable production of presenter-style videos without cameras, actors, or studio setups.
API Options
Platform-level options for task execution and delivery.
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taskType
string required value: videoInference -
Identifier for the type of task being performed
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taskUUID
string required UUID v4 -
UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task.
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outputType
string default: URL -
Video output type.
Allowed values 1 value
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outputFormat
string default: MP4 -
Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities.
- `MP4`: Widely supported video container (H.264), recommended for general use.
- `WEBM`: Optimized for web delivery.
- `MOV`: QuickTime format, common in professional workflows (Apple ecosystem).
Allowed values 3 values
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outputQuality
integer min: 20 max: 99 default: 95 -
Compression quality of the output. Higher values preserve quality but increase file size.
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webhookURL
string URI -
Specifies a webhook URL where JSON responses will be sent via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available.
Learn more 1 resource
- Webhooks PLATFORM
- Webhooks
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deliveryMethod
string default: async -
Determines how the API delivers task results.
Allowed values 1 value
- Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse. Required for long-running tasks like video generation.
Learn more 1 resource
- Task Polling PLATFORM
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uploadEndpoint
string URI -
Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials.
Common use cases:
- Cloud storage: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs.
- CDN integration: Upload to content delivery networks for immediate distribution.
// S3 presigned URL for secure upload https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600 // Google Cloud Storage presigned URL https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789 // Custom storage endpoint https://storage.example.com/uploads/generated-image.jpgThe content data will be sent as the request body to the specified URL when generation is complete.
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safety
object -
Content safety checking configuration for video generation.
Properties 2 properties
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safety»checkContentcheckContent
boolean default: false -
Enable or disable content safety checking. When enabled, defaults to
fastmode.
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safety»modemode
string default: none -
Safety checking mode for video generation.
Allowed values 3 values
- Disables checking.
- Checks key frames.
- Checks all frames.
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ttl
integer min: 60 -
Time-to-live (TTL) in seconds for generated content. Only applies when
outputTypeisURL.
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includeCost
boolean default: false -
Include task cost in the response.
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numberResults
integer min: 1 max: 4 default: 1 -
Number of results to generate. Each result uses a different seed, producing variations of the same parameters.
Inputs
Input resources for the task (images, audio, etc). These must be nested inside the inputs object.
inputs object.-
inputs»imageimage
string -
Image to animate as an avatar (UUID, URL, Data URI, or Base64).
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inputs»audioaudio
string -
Audio input (UUID or URL).
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inputs»avataravatar
string -
HeyGen avatar ID for a photo or video avatar.
Allowed values 513 values
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inputs»backgroundbackground
string -
Background image for the generated video (UUID, URL, Data URI, or Base64).
Core Parameters
Primary parameters that define the task output.
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model
string required value: heygen:avatar@4 -
Identifier of the model to use for generation.
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positivePrompt
string min: 1 max: 5000 -
Text prompt describing elements to include in the generated output.
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width
integer paired with height -
Width of the generated media in pixels.
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height
integer paired with width -
Height of the generated media in pixels.
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resolution
string -
Resolution preset for the output. When used with input media, automatically matches the aspect ratio from the input.
Allowed values 2 values
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speech
object -
Settings for speech generation.
Properties 5 properties
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speech»texttext
string -
Text to convert to speech.
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speech»voicevoice
string -
Voice identifier to use for speech generation.
Allowed values 2300 values
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speech»languagelanguage
string min: 1 -
Language code for speech generation.
Allowed values 186 values
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speech»speedspeed
float min: 0.5 max: 1.5 step: 0.01 default: 1 -
Playback speed of the generated speech.
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speech»pitchpitch
float min: -50 max: 50 step: 0.1 default: 0 -
Pitch adjustment for the voice.
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Settings
Technical parameters to fine-tune the inference process. These must be nested inside the settings object.
settings object.-
settings»backgroundColorbackgroundColor
string -
Hex color code for solid background (e.g. #ff0000).
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settings»expressivenessexpressiveness
string default: low -
Controls the level of avatar expressiveness.
Allowed values 3 values
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settings»removeBackgroundremoveBackground
boolean default: false -
Remove the avatar background. Video avatars must be trained with matting enabled.