HeyGen Avatar III overview
HeyGen Avatar III by HeyGen
HeyGen built Avatar III around a photo-to-video pipeline for photo avatars and video avatars, including digital twins and studio avatars. It differs from the older Avatar III engine in HeyGen's legacy v1 and v2 endpoints.
HeyGen Avatar III specs
- Model ID
heygen/avatar-iii- Developer
- HeyGen
- Input
- Image, Text, Video
- Output
- Video
- Endpoint
POST https://api.aimlapi.com/v2/video/generations
Pair a supported avatar look with a script
HeyGen says Avatar III accepts a supported avatar look together with a script and generates the video from that pair. It does not support cross-reference animation.
Check that your avatar look is one the engine supports before you build a workflow around it.
Set aspect ratio and resolution
The aspect ratio option accepts 16:9, 9:16, 1:1, 4:5, 5:4 or auto. Auto keeps the aspect ratio of the source and falls back to 16:9 when the source ratio cannot be read. Start with auto, then set an explicit ratio such as 9:16 when the destination needs a fixed shape.
The resolution option offers 720p or 1080p. Render a first pass at 720p to check the avatar and the script, then switch to 1080p for the final file.
Avatar III, IV or V
Avatar III is the fastest HeyGen engine. HeyGen recommends it for its dedicated photo-to-video pipeline, Avatar IV for broader coverage and Avatar V for the highest-fidelity motion and lip-sync. Avatar IV also adds control over gestures and expressiveness for photo avatars.
If lip-sync matters most, render the same script and avatar on Avatar III and Avatar V. Compare how closely the mouth movement follows the audio before you choose.
Use cases
Turn a written script into a talking-avatar video using a HeyGen photo avatar.
Animate a studio avatar or digital twin with a recorded audio track.
Render the same avatar video in 9:16, 1:1 and 16:9 for different placements.
Produce 720p draft renders to review a script before a 1080p final.
HeyGen Avatar III API pricing
| Usage | Price | Unit |
|---|---|---|
| Video generation | $0.017 |
Prices from the AI/ML API price list, checked on Nov 12, 2026.
How to use the HeyGen Avatar III API
View docs
Build with your agent
Give your agent the model details, code and documentation.
1Get your API key
Create API keyexport AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"2Make your first request
curl 'https://api.aimlapi.com/v2/video/generations' \
-H "Authorization: Bearer $AIMLAPI_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "heygen/avatar-iii",
"avatar_id": null
}'import os
import requests
headers = {
"Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
"Content-Type": "application/json",
}
payload = {
"model": "heygen/avatar-iii",
"avatar_id": null
}
response = requests.post("https://api.aimlapi.com/v2/video/generations", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())const response = await fetch("https://api.aimlapi.com/v2/video/generations", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
"model": "heygen/avatar-iii",
"avatar_id": null
}),
});
if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());The request returns a generation id. Poll GET https://api.aimlapi.com/v2/video/generations?generation_id=<id> until the status is completed.
Models similar to HeyGen Avatar III
HeyGen Avatar III FAQ
How much does HeyGen Avatar III cost?
HeyGen Avatar III costs $0.017 on AI/ML API, billed as you go with no subscription.
What inputs does HeyGen Avatar III need?
It needs a supported HeyGen avatar look and either a script or an audio track. The output is a talking-avatar video.
Which aspect ratios can I set?
The options are 16:9, 9:16, 1:1, 4:5, 5:4 and auto. Auto keeps the aspect ratio of the source and uses 16:9 when that ratio cannot be read.
Does Avatar III support cross-reference animation?
No. HeyGen states that Avatar III supports digital twins and photo avatars but does not support cross-reference animation.
Which output resolutions can I request?
The resolution option on this endpoint offers 720p or 1080p. HeyGen says Avatar III supports up to 4K for digital twins and studio avatars and limits photo avatars to 1080p.
What is the HeyGen Avatar III model ID?
Use heygen/avatar-iii as the model parameter. Requests go to https://api.aimlapi.com/v2/video/generations with your AI/ML API key.