HeyGen Lipsync Precision overview
HeyGen Lipsync Precision by HeyGen
HeyGen offers Precision as the higher-fidelity mode of its lipsync engine, next to Speed mode. It runs on avatar inference and trades longer processing time for lip-sync fidelity.
HeyGen Lipsync Precision specs
- Model ID
heygen/lipsync-precision- Developer
- HeyGen
- Input
- Image, Text, Video
- Output
- Video
- Endpoint
POST https://api.aimlapi.com/v2/video/generations
Where the longer processing time pays off
HeyGen recommends Precision mode for cinematic content and other videos where lip-sync fidelity matters. It also recommends it for side profiles, speaker switches, camera-angle changes, facial occlusions and complex multi-person conversations.
HeyGen says the engine can synchronize every visible face in a scene when speakers switch. Footage with several people on screen is therefore a natural test for this mode.
Prepare the video and the new audio
The model takes a source video and a replacement audio track. The original audio is replaced, and the speaker's mouth is re-animated to follow the new track.
Start with a short clip that contains your hardest shot, such as a side profile or a speaker switch. Check the mouth movement in those frames before you process a full-length video.
Precision or Speed
HeyGen Lipsync Speed also re-voices a video so the speaker's lips follow a new audio track. It finishes faster, while Precision gives higher fidelity.
Run the same clip through both modes. Choose Speed if the result is good enough for your footage, and Precision if the mouth movement drifts.
Use cases
Re-voice a cinematic scene with a new audio track while keeping the lip movement frame accurate.
Replace the audio of a long-form video with a new recording and re-animate the speaker's mouth to match.
Fix lip sync in a multi-person conversation where speakers switch and several faces are visible.
Re-voice footage with side profiles, camera-angle changes or partly covered faces.
HeyGen Lipsync Precision API pricing
| Usage | Price | Unit |
|---|---|---|
| Video generation | $0.029 | per second |
Prices from the AI/ML API price list, checked on Nov 12, 2026.
HeyGen Lipsync Precision vs other video models: prices
AI/ML API rates for 5 models, per second.
| Model | Per second |
|---|---|
 HeyGen Lipsync Precision | $0.029 |
 MiniMax H3 Lite | $0.025 |
 Kling AI (text-to-video) | $0.029 |
 Veo 3.1 Lite Generate Preview | $0.03 |
| Veo 3.1 Lite | $0.03 |
How to use the HeyGen Lipsync Precision 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/lipsync-precision",
"video_url": "https://example.com/input.mp3",
"audio_url": "https://example.com/input.mp3"
}'import os
import requests
headers = {
"Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
"Content-Type": "application/json",
}
payload = {
"model": "heygen/lipsync-precision",
"video_url": "https://example.com/input.mp3",
"audio_url": "https://example.com/input.mp3"
}
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/lipsync-precision",
"video_url": "https://example.com/input.mp3",
"audio_url": "https://example.com/input.mp3"
}),
});
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 Lipsync Precision
HeyGen Lipsync Precision FAQ
How much does HeyGen Lipsync Precision cost?
HeyGen Lipsync Precision costs $0.029 / sec on AI/ML API.
What do I need to send to this model?
Send a source video and the replacement audio track. The model replaces the original audio and re-animates the speaker's lips to match the new one.
When should I choose Precision over Speed?
HeyGen recommends Precision for cinematic content and videos where lip-sync fidelity matters. Precision takes longer to process than Speed, so use Speed when that fidelity is not needed.
Does it work when several people are on screen?
HeyGen says the lipsync engine can synchronize every visible face when speakers switch. It also recommends Precision mode for complex multi-person conversations.
Which shots are hardest for lip sync?
HeyGen recommends Precision for side profiles, camera-angle changes and facial occlusions. Include these shots in your first test clip.
What is the HeyGen Lipsync Precision model ID?
Use heygen/lipsync-precision as the model parameter. Requests go to https://api.aimlapi.com/v2/video/generations with your AI/ML API key.