> ## Documentation Index > Fetch the complete documentation index at: https://fal.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Kling Video Lipsync API > API reference for Kling Video Lipsync. Kling LipSync is an audio-to-video model that generates realistic lip movements from audio input. **Endpoint:** `POST https://fal.run/fal-ai/kling-video/lipsync/audio-to-video` **Endpoint ID:** `fal-ai/kling-video/lipsync/audio-to-video` Run this model interactively with your own prompts. ### Quick Start ```python title="Python" theme={null} import fal_client def on_queue_update(update): if isinstance(update, fal_client.InProgress): for log in update.logs: print(log["message"]) result = fal_client.subscribe( "fal-ai/kling-video/lipsync/audio-to-video", arguments={ "video_url": "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", "audio_url": "https://storage.googleapis.com/falserverless/kling/kling-audio.mp3" }, with_logs=True, on_queue_update=on_queue_update, ) print(result) ``` ```javascript title="JavaScript" theme={null} import { fal } from "@fal-ai/client"; const result = await fal.subscribe("fal-ai/kling-video/lipsync/audio-to-video", { input: { video_url: "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", audio_url: "https://storage.googleapis.com/falserverless/kling/kling-audio.mp3" }, logs: true, onQueueUpdate: (update) => { if (update.status === "IN_PROGRESS") { update.logs.map((log) => log.message).forEach(console.log); } }, }); console.log(result.data); console.log(result.requestId); ``` ```bash title="cURL" theme={null} curl --request POST \ --url https://fal.run/fal-ai/kling-video/lipsync/audio-to-video \ --header "Authorization: Key $FAL_KEY" \ --header "Content-Type: application/json" \ --data '{ "video_url": "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", "audio_url": "https://storage.googleapis.com/falserverless/kling/kling-audio.mp3" }' ``` ### Input Schema The URL of the video to generate the lip sync for. Supports .mp4/.mov, ≤100MB, 2–10s, 720p/1080p only, width/height 720–1920px. The URL of the audio to generate the lip sync for. Minimum duration is 2s and maximum duration is 60s. Maximum file size is 5MB. ### Output Schema The generated video ### Input Example ```json theme={null} { "video_url": "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", "audio_url": "https://storage.googleapis.com/falserverless/kling/kling-audio.mp3" } ``` ### Output Example ```json theme={null} { "video": { "url": "https://storage.googleapis.com/falserverless/kling/kling_output.mp4" } } ``` **Endpoint:** `POST https://fal.run/fal-ai/kling-video/lipsync/text-to-video` **Endpoint ID:** `fal-ai/kling-video/lipsync/text-to-video` Run this model interactively with your own prompts. ### Quick Start ```python title="Python" theme={null} import fal_client def on_queue_update(update): if isinstance(update, fal_client.InProgress): for log in update.logs: print(log["message"]) result = fal_client.subscribe( "fal-ai/kling-video/lipsync/text-to-video", arguments={ "video_url": "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", "text": "Mental health is as important as physical health, shaping our emotions, thoughts, and daily interactions.", "voice_id": "genshin_klee2" }, with_logs=True, on_queue_update=on_queue_update, ) print(result) ``` ```javascript title="JavaScript" theme={null} import { fal } from "@fal-ai/client"; const result = await fal.subscribe("fal-ai/kling-video/lipsync/text-to-video", { input: { video_url: "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", text: "Mental health is as important as physical health, shaping our emotions, thoughts, and daily interactions.", voice_id: "genshin_klee2" }, logs: true, onQueueUpdate: (update) => { if (update.status === "IN_PROGRESS") { update.logs.map((log) => log.message).forEach(console.log); } }, }); console.log(result.data); console.log(result.requestId); ``` ```bash title="cURL" theme={null} curl --request POST \ --url https://fal.run/fal-ai/kling-video/lipsync/text-to-video \ --header "Authorization: Key $FAL_KEY" \ --header "Content-Type: application/json" \ --data '{ "video_url": "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", "text": "Mental health is as important as physical health, shaping our emotions, thoughts, and daily interactions.", "voice_id": "genshin_klee2" }' ``` ### Input Schema The URL of the video to generate the lip sync for. Supports .mp4/.mov, ≤100MB, 2-60s, 720p/1080p only, width/height 720–1920px. If validation fails, an error is returned. Text content for lip-sync video generation. Max 120 characters. Voice ID to use for speech synthesis Possible values: `genshin_vindi2`, `zhinen_xuesheng`, `AOT`, `ai_shatang`, `genshin_klee2`, `genshin_kirara`, `ai_kaiya`, `oversea_male1`, `ai_chenjiahao_712`, `girlfriend_4_speech02`, `chat1_female_new-3`, `chat_0407_5-1`, `cartoon-boy-07`, `uk_boy1`, `cartoon-girl-01`, `PeppaPig_platform`, `ai_huangzhong_712`, `ai_huangyaoshi_712`, `ai_laoguowang_712`, `chengshu_jiejie`, `you_pingjing`, `calm_story1`, `uk_man2`, `laopopo_speech02`, `heainainai_speech02`, `reader_en_m-v1`, `commercial_lady_en_f-v1`, `tiyuxi_xuedi`, `tiexin_nanyou`, `girlfriend_1_speech02`, `girlfriend_2_speech02`, `zhuxi_speech02`, `uk_oldman3`, `dongbeilaotie_speech02`, `chongqingxiaohuo_speech02`, `chuanmeizi_speech02`, `chaoshandashu_speech02`, `ai_taiwan_man2_speech02`, `xianzhanggui_speech02`, `tianjinjiejie_speech02`, `diyinnansang_DB_CN_M_04-v2`, `yizhipiannan-v1`, `guanxiaofang-v2`, `tianmeixuemei-v1`, `daopianyansang-v1`, `mengwa-v1` The voice language corresponding to the Voice ID Default value: `"en"` Possible values: `zh`, `en` Speech rate for Text to Video generation Default value: `1` Range: `0.8` to `2` ### Output Schema The generated video ### Input Example ```json theme={null} { "video_url": "https://fal.media/files/koala/8teUPbRRMtAUTORDvqy0l.mp4", "text": "Mental health is as important as physical health, shaping our emotions, thoughts, and daily interactions.", "voice_id": "genshin_klee2", "voice_language": "en", "voice_speed": 1 } ``` ### Output Example ```json theme={null} { "video": { "url": "https://storage.googleapis.com/falserverless/kling/kling_text_lipsync.mp4" } } ``` Kuaishou's Kling LipSync generates realistic lip-synchronized video from audio input in approximately 12 minutes at \$0.014 per 5-second increment. Trading speed for precision lip-sync accuracy, the model handles 2-10 second source videos with audio up to 60 seconds. Purpose-built for dubbing, content localization, and audio-driven character animation where **mouth movement realism** matters more than generation time. **Use Cases:** Video Dubbing & Translation | Audio-Driven Character Animation | Content Localization for Global Markets *** ## Performance At \$0.014 per 5-second video increment (rounded up), Kling LipSync positions as a specialized audio-to-video tool trading inference speed for **lip-sync precision**. Processing takes approximately 12 minutes regardless of video duration within the 2-10 second input range. | Metric | Result | Context | | :----------------------- | :----------------------- | :--------------------------------------------------- | | **Inference Speed** | \~12 minutes | Fixed processing time for 2-10s input videos | | **Cost per Video** | \$0.014 per 5s increment | Billed in 5-second increments (3s video = 5s charge) | | **Input Video Duration** | 2-10 seconds | 720p/1080p, ≤100MB, .mp4/.mov only | | **Audio Duration** | 2-60 seconds | ≤5MB file size, .mp3/.wav/.ogg/.m4a/.aac formats | | **Resolution Support** | 720p-1080p | Width/height constrained to 720-1920px | *** ## Precision Lip-Sync Without Training Data Kling LipSync uses audio-driven facial animation architecture that generates mouth movements directly from audio waveforms without requiring speaker-specific training data, contrasting with traditional lip-sync approaches that need extensive footage of the target speaker. **What this means for you:** * **Zero-shot speaker adaptation:** Sync any audio to any face without pre-training on that specific person, enabling rapid dubbing workflows across multiple speakers and languages * **Extended audio support:** Process up to 60 seconds of audio against 2-10 second video clips, useful for looping background characters or extending dialogue beyond source footage length * **Format flexibility:** Accepts 5 audio formats (.mp3, .wav, .ogg, .m4a, .aac) and standard video containers (.mp4, .mov), integrating into existing [video generation workflows](https://fal.ai/models) without format conversion overhead * **Increment-based pricing transparency:** 5-second billing increments mean predictable costs (a 3-second video costs the same as 5 seconds at $0.014, a 7-second video bills as 10 seconds at $0.028) *** ## Technical Specifications | Spec | Details | | :-------------------------- | :------------------------------------------------------------------------------------ | | **Architecture** | Kling LipSync | | **Input Formats** | Video: .mp4, .mov (2-10s, ≤100MB) / Audio: .mp3, .wav, .ogg, .m4a, .aac (2-60s, ≤5MB) | | **Output Formats** | .mp4 video with synchronized lip movements | | **Resolution Requirements** | 720p or 1080p input, width/height 720-1920px | | **License** | Commercial use via fal partnership | [API Documentation](https://fal.ai/models/fal-ai/kling-video/lipsync/audio-to-video/api) | [Quickstart Guide](https://docs.fal.ai/model-apis/quickstart) | [Enterprise Pricing](https://fal.ai/pricing) ## Related * [Kling LipSync Text-to-Video](/model-api-reference/video-generation-api/kling-lipsync-text-to-video) — Video Generation * [Kling LipSync Audio-to-Video](/model-api-reference/video-generation-api/kling-lipsync-audio-to-video) — Video Generation ## Limitations * `voice_language` restricted to: `zh`, `en` * `voice_speed` range: 0.8 to 2