Create personalized avatar videos using the HeyGen Avatar IV API. This guide walks you through generating avatar videos from a single photo with AI-powered motion, expressions, and voice.

1. Upload Photo

Before generating a video, upload your photo using the Upload Asset API. This will return an image_key, which is required for the Avatar IV video.

2. Prepare Script and Voice

Your video requires:

• Script - text that the avatar will speak.
• Voice - you must provide a voice_id, obtained from the List All Voices (V2) API.

Additionally, you can provide a custom audio recording using:

• audio_url - URL of a custom audio file.
• audio_asset_id - HeyGen asset ID of an audio file.

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The voice_id is a required parameter.

Customize Motion

Avatar IV Video also supports custom motion prompts, allowing you to guide the avatar’s gestures and expressions. Use descriptive prompts in the custom_motion_prompt field. Set enhance_custom_motion_prompt to true to let AI refine the motion.

Motion results depend on the script and prompt; the API does not require predefined gestures.

3. Generate Video

Make a POST request to the Create Avatar IV Video API with the required parameters: image_key, video_title, script, and voice_id.

For full request and response details, see detailed API reference: Create Avatar IV Video.

Conclusion

You’ve now created an Avatar IV video using the HeyGen API. This guide walked you through all key steps - uploading a photo, preparing the script and voice, and generating the Avatar IV video.