{"observation":{"id":"3f569910-d750-4754-8623-e5774a7e1ddb","tool":"heygen","tool_name":"Heygen","criterion":"lip-sync-accuracy","criterion_name":"Lip Sync Accuracy","criterion_definition":"Does the dubbed audio visually match lip movements in the original video?","criterion_evidence_type":"transformation","criterion_rank_role":"decisive","criterion_rank_role_reason":"If the dubbed audio does not match the on-screen mouth movements, the core purpose of video translation with lip sync has failed. (3 of 3 judges)","scenario":"hindi-vlog-style-talking-head-hindi-english","scenario_name":"Hindi vlog-style talking head (Hindi → English)","group_tag":"video-translation-voice-clone-lip-sync","scenario_description":"A casual Hindi/Hinglish talking-head or vlog-style creator video translated into English to stress informal language handling, slang, and natural-sounding voice cloning on real creator content.","modality":"video","input_text":null,"input_artifact_refs":[],"stresses":[],"verdict":"mixed","score":null,"score_total":null,"note":"Lip sync is acceptable, but it weakens on longer sentences.","evidence_state":"verified","source":"first-party","artifacts":[{"url":"https://d3epheqghktydj.cloudfront.net/heygen-input-2-educational.mp4","role":"input","alt":"HeyGen — Input 2 Educational.mp4"}],"run_id":"9feca581-b454-4bda-a610-a646cd0092f0","study_title":"Translate Videos with Voice Cloning and Lip Sync Using AI","study_kind":"backfill","research_task":"86b96dfpf","tested_at":"2026-06-24T05:45:24.018000+00:00","completeness":"input-only","input":{"state":"not-captured","text":null,"files":[],"modality":"video","stresses":[]},"tool_page_slug":"heygen","tool_url":"https://aidemos.com/tools/heygen","permalink":"https://aidemos.com/evidence/3f569910-d750-4754-8623-e5774a7e1ddb","api_url":"https://ai.aidemos.com/v1/observations/3f569910-d750-4754-8623-e5774a7e1ddb"},"peers":[{"id":"d29db857-29b4-4b28-9e92-85d3759bd67f","tool":"d-id","tool_name":"D-ID","verdict":"failed","score":null,"score_total":null,"note":"Lip sync worked well on the AI avatar, but it did not apply to the original video.","artifact_count":1,"thumbnail":"https://d3epheqghktydj.cloudfront.net/d-id-d-id-educationalvideo-en-es-mp4.mp4","evidence_url":"https://aidemos.com/evidence/d29db857-29b4-4b28-9e92-85d3759bd67f"},{"id":"037db325-ec97-4d49-b00c-d6727c04a9fc","tool":"dubverse","tool_name":"Dubverse","verdict":"worked","score":null,"score_total":null,"note":"Achieves more precise lip sync than the other tested inputs.","artifact_count":2,"thumbnail":"https://d3epheqghktydj.cloudfront.net/dubverse-input-2-educational.mp4","evidence_url":"https://aidemos.com/evidence/037db325-ec97-4d49-b00c-d6727c04a9fc"},{"id":"d3cdcec4-eba0-4bd3-a162-9fe73d634781","tool":"elevenlabs","tool_name":"ElevenLabs","verdict":"failed","score":null,"score_total":null,"note":"Provides no built-in lip sync or video integration, so the dubbed audio cannot visually align with the original mouth movements inside the tool.","artifact_count":2,"thumbnail":"https://d3epheqghktydj.cloudfront.net/elevenlabs-input-1-fitness-video-online-video-cutter-com.mp4","evidence_url":"https://aidemos.com/evidence/d3cdcec4-eba0-4bd3-a162-9fe73d634781"},{"id":"0e34ffc2-0cda-4bf1-b391-b14cf3fc038c","tool":"rask-ai","tool_name":"Rask AI","verdict":"mixed","score":null,"score_total":null,"note":"Performs better on slower, clearer speech, but still shows slight lip-movement delays in some frames.","artifact_count":1,"thumbnail":"https://d3epheqghktydj.cloudfront.net/rask-ai-input-2-educational.mp4","evidence_url":"https://aidemos.com/evidence/0e34ffc2-0cda-4bf1-b391-b14cf3fc038c"},{"id":"99c929a8-85a1-45db-a74c-9b5616555ccd","tool":"sync-labs","tool_name":"Sync Labs","verdict":"mixed","score":null,"score_total":null,"note":"Lip sync worked overall, but it struggled during expressive facial movements and fast speech.","artifact_count":2,"thumbnail":"https://d3epheqghktydj.cloudfront.net/sync-labs-free-copyright-stock-videos-images-and-music-publer-com-online-video-cutter-com.mp4","evidence_url":"https://aidemos.com/evidence/99c929a8-85a1-45db-a74c-9b5616555ccd"}],"other_criteria":[{"id":"ea512218-b5f2-4cc1-bbda-d81fec54ede7","criterion":"translation-accuracy","criterion_name":"Translation Accuracy","rank_role":"decisive","verdict":"worked","score":null,"score_total":null,"note":"Produces mostly accurate English→Spanish translation for structured educational narration.","artifact_count":1,"evidence_url":"https://aidemos.com/evidence/ea512218-b5f2-4cc1-bbda-d81fec54ede7"},{"id":"c2fcd871-7f4f-4820-94c7-92f755da2835","criterion":"translation-accuracy","criterion_name":"Translation Accuracy","rank_role":"decisive","verdict":"worked","score":null,"score_total":null,"note":"Produces a semantically accurate English→Hindi translation that preserves the energetic fitness tone.","artifact_count":1,"evidence_url":"https://aidemos.com/evidence/c2fcd871-7f4f-4820-94c7-92f755da2835"},{"id":"35c74480-d28a-4b69-b1ff-ddf6adb189a4","criterion":"translation-accuracy","criterion_name":"Translation Accuracy","rank_role":"decisive","verdict":"mixed","score":null,"score_total":null,"note":"Produces an understandable English translation, but it becomes literal and loses natural conversational flow.","artifact_count":1,"evidence_url":"https://aidemos.com/evidence/35c74480-d28a-4b69-b1ff-ddf6adb189a4"},{"id":"93225df6-a800-4a70-91b5-cd29e8e95ceb","criterion":"voice-cloning-quality","criterion_name":"Voice Cloning Quality","rank_role":"decisive","verdict":"mixed","score":null,"score_total":null,"note":"The dubbed voice sounds slightly robotic rather than fully natural.","artifact_count":1,"evidence_url":"https://aidemos.com/evidence/93225df6-a800-4a70-91b5-cd29e8e95ceb"},{"id":"03d5ccd4-d2d5-4ec2-8443-8900e80b640c","criterion":"voice-cloning-quality","criterion_name":"Voice Cloning Quality","rank_role":"decisive","verdict":"struggled","score":null,"score_total":null,"note":"The dubbed voice does not fully match the speaker's casual conversational tone.","artifact_count":1,"evidence_url":"https://aidemos.com/evidence/03d5ccd4-d2d5-4ec2-8443-8900e80b640c"},{"id":"ce503b73-2ecf-45f4-b807-c18269db157d","criterion":"voice-cloning-quality","criterion_name":"Voice Cloning Quality","rank_role":"decisive","verdict":"worked","score":null,"score_total":null,"note":"Generates a dubbed voice whose tone matches the original speaker's energetic fitness style.","artifact_count":1,"evidence_url":"https://aidemos.com/evidence/ce503b73-2ecf-45f4-b807-c18269db157d"}],"appears_in":[{"page_type":"ranking","slug":"ai-video-dubbing-tools","title":"Best AI Tools to Translate Videos with Voice Cloning and Lip Sync","url":"https://aidemos.com/best/ai-video-dubbing-tools","binding":"run"}],"same_scenario":[{"id":"d29db857-29b4-4b28-9e92-85d3759bd67f","tool":"d-id","tool_name":"D-ID","verdict":"failed","score":null,"score_total":null,"note":"Lip sync worked well on the AI avatar, but it did not apply to the original video."},{"id":"037db325-ec97-4d49-b00c-d6727c04a9fc","tool":"dubverse","tool_name":"Dubverse","verdict":"worked","score":null,"score_total":null,"note":"Achieves more precise lip sync than the other tested inputs."},{"id":"d3cdcec4-eba0-4bd3-a162-9fe73d634781","tool":"elevenlabs","tool_name":"ElevenLabs","verdict":"failed","score":null,"score_total":null,"note":"Provides no built-in lip sync or video integration, so the dubbed audio cannot visually align with the original mouth movements inside the tool."},{"id":"0e34ffc2-0cda-4bf1-b391-b14cf3fc038c","tool":"rask-ai","tool_name":"Rask AI","verdict":"mixed","score":null,"score_total":null,"note":"Performs better on slower, clearer speech, but still shows slight lip-movement delays in some frames."},{"id":"99c929a8-85a1-45db-a74c-9b5616555ccd","tool":"sync-labs","tool_name":"Sync Labs","verdict":"mixed","score":null,"score_total":null,"note":"Lip sync worked overall, but it struggled during expressive facial movements and fast speech."}]}