> For the documentation index, fetch https://sync.so/docs/llms.txt. Append .md to a page URL for Markdown. Documentation-search MCP: https://sync.so/docs/_mcp/server. # Speaker Selection — Studio > Select which speaker to lipsync in multi-person videos or images using sync. labs Studio. Manual face selection and active speaker detection guide. Speaker selection lets you pick which person gets lipsynced in a video or image with multiple people. You can manually click a face, or for videos, use Active Speaker Detection to let Sync Labs identify the speaker automatically. For programmatic usage via the API, see the [API guide](/developer-guides/speaker-selection). > **Info** > > Speaker selection is available with our **lipsync-2**, **lipsync-2-pro**, and **sync-3** models in both Lite and Advanced modes. Note that **react-1** does not currently support this feature. For **sync-3 image inputs**, only manual face selection is supported — Active Speaker Detection is video-only. ## Selecting a Speaker in Video #### Upload your video Upload a video that contains multiple people. Sync Labs detects the number of speakers in the background. ![Studio overview](/docs/_fern-img/3186a018c3a3793ac753d4e4ce85d95cac8798bc369e05c0e83385ae3f2def54.webp) #### Enable face detection Click the icon in the video player controls. Green bounding boxes appear around detected faces with a hint: "select which speaker to lipsync." ![Face detection active](/docs/_fern-img/8f311bfc412403f2576a4bad7c6b7a4a48fc4515ad6c45e56f538dcb5c1fff9d.webp) #### Click on the speaker's face Click on the bounding box of the person you want to lipsync. The selected face gets a bright green border and a face thumbnail appears in the controls. ![Face selected](/docs/_fern-img/7ecb682b906f34ac0effad75d953bcce50ea95ea2de99674fcee42783dda44c3.webp) #### Generate Click the Sync Labs button. The speaker configuration is sent automatically with your generation request. ## Changing or Clearing Your Selection * Click the **X** on the face thumbnail to clear your selection. * Scrubbing through the video re-runs detection. * Click another face to switch speakers. ## Active Speaker Detection As an alternative to manual selection, toggle **Active Speaker Detection** in the Studio settings panel. Sync Labs identifies the speaker via lip movement analysis — no manual click needed. > **Warning** > > Manual selection and Active Speaker Detection are mutually exclusive — you can only use one at a time. Active Speaker Detection may not work reliably on silent or low-motion clips. ## Selecting a Speaker in Images (sync-3) For images with multiple faces, you can select which person to lipsync using the same face detection overlay. #### Upload your image Upload an image with the sync-3 model selected. Face detection runs automatically when the image loads. #### Click on the speaker's face If multiple faces are detected, click on the face you want to lipsync. The selected face gets a bright green border and appears in the controls. #### Generate Click the Sync Labs button. The speaker coordinates are sent with your generation request. > **Info** > > Active Speaker Detection is not available for image inputs — only manual face selection. If your image contains a single face, the system skips the selection step automatically.