Lip Sync AI

Lip sync works by re-drawing the mouth area frame by frame, so the model needs to see the mouth clearly in the source video.

• One face, clearly visible. A front or three-quarter view works best. Side profiles, hands in front of the face or fast head turns reduce quality.
• Good resolution. 720p to 1080p footage gives the model enough detail. Very small faces in a wide shot are hard to sync.
• Match the lengths. The result is as long as the video, so trim the audio to the clip length. Extra audio is cut off.
• Clean audio. A clear voice with little music or background noise syncs better. Separate the vocals from a song first with the AI Vocal Remover.
• Stay in the limits. The video must be 2 to 10 seconds and under 50 MB; the audio must be under 5 MB.

For longer scenes, cut the video into 10 second parts, sync each part with its matching slice of audio, and join them in your editor.

Timing matters as well. If the new audio has long pauses, the mouth will close during them, so trim silences you do not want. If the original clip shows the person talking, their speech rhythm may still show in the head and jaw movement, so similar pacing in the new audio gives the most natural result.

RegiAI has a few tools that change faces in video. They solve different problems:

• Lip Sync AI keeps the person and changes only what they say. Start from a video and an audio file.
• AI Talking Photo starts from a single photo and a typed script, and generates both the voice and the motion.
• AI Face Swap Video changes who is in the video, but keeps the original audio and mouth movement.
• AI Character Replace replaces the whole person with a character from an image.

A common dubbing workflow is: transcribe or translate the speech with the AI Audio Translator, then lip sync the clip to the new track here. Add subtitles for viewers who watch muted with the AI Subtitle Generator.

If you do not have a voice track yet, the AI Voice Generator turns text into natural speech, and the AI Voice Cloner can match a voice from a short sample you have permission to use.

Not sure which one you need? If the words should change, use lip sync. If the face should change, use face swap. If you are starting from a photo, use talking photo.

Each lip sync costs $0.35 for a video of up to 10 seconds, paid per use from your balance. There is no subscription and no watermark. If a sync fails, the $0.35 goes back to your balance automatically.

Before you generate, you confirm that you have permission to use the face in the video. Lip sync can put words in someone's mouth, so only use it on yourself, on people who agreed, or on characters you own. Never use it to impersonate a real person, spread false statements, harass anyone or create sexual content.

When you publish a lip-synced video of a real person, label it as AI-edited. Dubbing a video you made yourself into another language is a great use; making a public figure appear to say something they never said is not allowed.

Tip for dubbing projects: sync a single 10 second test clip before you process a whole video. At $0.35 per clip, it is a cheap way to check that the voice, pacing and face angle work together.