audiostring
URL of an audio file for the avatar to lip-sync to. When provided, overrides prompt and voice.
HeyGen Avatar 4 Image to Video
heygen/heygen-avatar4/image-to-videoHeygen Avatar4 is HeyGen's image-to-video AI model. Bring static images to life with fluid animation, consistent character motion, and professional-grade video output.
Try the model
Playground
Input
The text the avatar will speak
PNG, JPEG, WebP, or GIF · 20 MiB maximum
URL of the image to animate. The image should contain a clear face.
This field is required.
Additional Settings More
Customize your input with more control.
URL of an audio file for the avatar to lip-sync to. When provided, overrides prompt and voice.
Output aspect ratio. Omit to keep the source aspect ratio (falls back to 16:9 when it cannot be read). Allowed values: 16:9, 9:16, 4:5, 5:4, 1:1.
The voice ID to use for the avatar.
Video resolution preset. Allowed values: 360p, 480p, 540p, 720p, 1080p.
Talking style: 'stable' for minimal movement, 'expressive' for more animation. Allowed values: stable, expressive.
ResultExample
What would you like to do next?
Examples
Select an example to load its inputs and result into the playground.
- Open result ↗
Input
{ "image": "https://static.sandbase.ai/examples/58f680f7-93d6-4f27-9255-0043d7b5c44c/input/48d5dacb-cf6b-4678-a54d-dd7bc01337fb.png", "prompt": "Hey friends! Welcome to the GPU force podcast and today we are going to discuss about the rising GPU cost!" }
HeyGen Avatar 4 Image to Video
HeyGen Avatar 4: turn a single photo into a talking presenter, driven by a script or an audio track.
Fields
| Field | Type | Default | Notes |
|---|---|---|---|
prompt | string | — | Script to speak. |
image | image URL, required | — | Photo of the presenter. JPEG, PNG, or WebP URL. |
audio | audio URL | — | Optional voice track. |
aspect_ratio | 16:9 / 9:16 / 4:5 / 5:4 / 1:1 | — | Output frame shape. |
voice | string | Melissa | Voice for the script. |
resolution | 360p / 480p / 540p / 720p / 1080p | 720p | Video resolution preset. |
talking_style | stable / expressive | stable | expressive adds more head and hand motion. |
Billing
$0.10 per output second; length follows the audio or the spoken script. The quote before submission assumes 5 seconds.
| Output | Price |
|---|---|
| 5s | $0.50 |
| 30s | $3.00 |
| 60s | $6.00 |
Failed runs are not charged.
Prompting
- Use a front-facing photo with the face clearly visible.
Also on SandBase
Related: heygen/avatar5/digital-twin.
Start building
Send your first request
Submit this model through the SandBase Unified Run API.
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
-X POST "https://api.sandbase.ai/v1/run" \
-H "Authorization: Bearer $SANDBASE_API_KEY" \
-H "Content-Type: application/json" \
--data-binary @- <<'SANDBASE_JSON'
{
"model": "heygen/heygen-avatar4/image-to-video",
"image": "https://v3b.fal.media/files/b/0a90062c/A7EIviZqNxZ2HAs0yHeZ6_77a05b99-8588-4ffc-90aa-be7f9d34e9d3.png",
"voice": "Melissa",
"prompt": "Hey friends! Welcome to the GPU force podcast and today we are going to discuss about the rising GPU cost!",
"resolution": "720p",
"talking_style": "stable"
}
SANDBASE_JSON
)
run_id=$(printf '%s' "$result" | jq -r .id)
for attempt in $(seq 1 120); do
status=$(printf '%s' "$result" | jq -r .status)
case "$status" in completed|failed|timeout) break ;; esac
sleep 2
result=$(curl --fail-with-body --silent \
-H "Authorization: Bearer $SANDBASE_API_KEY" \
"https://api.sandbase.ai/v1/run/$run_id")
done
status=$(printf '%s' "$result" | jq -r .status)
[ "$status" = completed ] || { echo "Generation ended: $status" >&2; exit 1; }
printf '%s\n' "$result"2. Authentication
Create a SandBase API key and set it in your server environment. All requests use Bearer authentication.
export SANDBASE_API_KEY="YOUR_API_KEY"Keep the key on your server. Do not expose it in browser code or commit it to a repository.
3. Queue
Submit a request
POST to /v1/run with this model ID and its inputs. The request example above includes submission and polling.
Fetch request status and result
Use the returned run ID to poll until the status is completed, failed or timeout. Read output only after completed.
curl "https://api.sandbase.ai/v1/run/$RUN_ID" \
-H "Authorization: Bearer $SANDBASE_API_KEY"4. Files
Hosted files
Pass a publicly accessible file URL in the model’s image, video or audio field. Supported formats and limits are shown beside each Playground input.
Uploading images
Use the upload or replace control on supported image fields in the Playground. Video URL fields accept a hosted driving video; they do not imply video-upload support.
5. Schema
Input
imagestringrequired
URL of the image to animate. The image should contain a clear face.
voicestring
The voice ID to use for the avatar.
Default: "Melissa"
promptstring
The text the avatar will speak
resolutionstring
Video resolution preset.
Default: "720p"
Possible values: "360p", "480p", "540p", "720p", "1080p"
aspect_ratiostring
Output aspect ratio. Omit to keep the source aspect ratio (falls back to 16:9 when it cannot be read).
Possible values: "16:9", "9:16", "4:5", "5:4", "1:1"
talking_stylestring
Talking style: 'stable' for minimal movement, 'expressive' for more animation.
Default: "stable"
Possible values: "stable", "expressive"
{
"model": "heygen/heygen-avatar4/image-to-video",
"image": "https://v3b.fal.media/files/b/0a90062c/A7EIviZqNxZ2HAs0yHeZ6_77a05b99-8588-4ffc-90aa-be7f9d34e9d3.png",
"voice": "Melissa",
"prompt": "Hey friends! Welcome to the GPU force podcast and today we are going to discuss about the rising GPU cost!",
"resolution": "720p",
"talking_style": "stable"
}Output
A completed run exposes its result in output. The following is the model’s saved example, not a new generation.
[
{
"poster": "https://static.sandbase.ai/examples/posters/a1f21fe6264568c9ddae.jpg",
"source": "heygen schema mirror",
"source_url": "https://heygen.example/",
"url": "https://static.sandbase.ai/examples/58f680f7-93d6-4f27-9255-0043d7b5c44c/output/3fac915a-6088-4da9-9af5-2ba18962809a.mp4"
}
]