# AI Video Translator: Dub, Lip Sync and Caption a Video (2026) > How an AI video translator works: the five parts of a complete dub, which tools cover each part, a free YouTube first step, and how to choose a platform. _Source: https://professionalstoolkit.com/articles/ai-video-translator — The Professional's Toolkit · updated November 2026_ _Part of: [Translate a video into another language, with subtitles or a dubbed voice](https://professionalstoolkit.com/solutions/translate-a-video) — the guide, the do-it-yourself version and the tools that do it_ --- Hand a finished video in one language to an **AI video translator** and it gives the video back in another: it transcribes the speech, translates the script, voices it again and, if a face is on screen, can re-sync the lips. No single click does all of that well. A complete solution has five parts, and the right tool is the one that covers the parts your video actually needs. Training teams usually need a cloned voice and a review step. Creators usually need captions plus a dub. Some people only need a mouth matched to audio they already have. **20-40%** — How much longer translated text can run than the original, per Synthesia's guidance - **5 parts** — Transcript, translation, voice, lip sync, on-screen text - **120 min** — Longest video YouTube auto dubbing accepts - **Up to 4K** — Source files Synthesia's dubbing accepts ## What a complete AI video translator setup needs Think of translation as a chain. A weak link anywhere shows up in the final video, and most bad dubs fail at the start of the chain, not the end. 1. **A clean transcript.** Every later step inherits its mistakes. Names, product terms and numbers are where it slips. 2. **A reviewed translation.** A fluent speaker of the target language reads it before any voice is made. Idioms, jargon and brand terms need a human eye. 3. **A voice.** Either a stock synthetic voice or a clone of the original speaker. You need the right to use the voice you clone. 4. **Lip sync, when a face is visible.** A dubbed voice over unmoving lips reads as dubbed. For screen recordings, slides or B-roll, skip this part. 5. **Everything that is not speech.** On-screen titles, burned-in captions and text in the footage are usually left in the original language. The last part is the one people forget. Most dubbing tools translate what is said, not what is written on screen. Plan for that before you start, not after the first export. > 💡 **Fix the transcript before translating:** Every later step copies transcript errors. Check names, product terms and numbers first, and the dub inherits clean text. The three levels of video translation map onto these parts. Translated subtitles need parts 1 and 2. A dub adds part 3. A dub with lip sync adds part 4. If you want the full background on the levels and when each is enough, read our guide to [video translation](/articles/video-translation) first; this page is about which tools cover which parts. ## For training and business videos: dub with the speaker's own voice Synthesia is built for businesses, and translating video is one of its main jobs. Its two routes split by where the video came from. AI Dubbing handles footage made anywhere. 1-Click Translation works only on videos made inside Synthesia, and there it keeps the avatar, scenes and design intact, which is why it can also reach part 5 of the chain. For a team with a library of recorded speakers, the first route is the one that matters. ### Synthesia — dubs in each speaker's cloned voice AI Dubbing takes an uploaded video or a YouTube link, transcribes and translates it, and voices it with a clone of each original speaker, with lip sync as an option. 1-Click Translation also translates on-screen text in videos made in Synthesia. 1. Upload the file or paste a YouTube link 2. Pick the target language and decide on lip sync 3. Check the estimate, dub, then review each language - Where it stops: Translates spoken audio only, not burned-in text; on Basic, dubs are watermarked with no MP4 download; videos dubbed from a YouTube link cannot be published on Basic, Starter or Pro. - Plan: Dubbing on all plans; MP4 download from Starter; 1-Click Translation, Review transcript and custom glossary on Enterprise - [Dubbing vs 1-Click Translation](https://professionalstoolkit.com/articles/synthesia-video-translation) · [Synthesia](https://professionalstoolkit.com/tools/synthesia) The plan details matter here. Dubbing is listed on every plan, but on Basic a dubbed video is watermarked and cannot be downloaded as an MP4. Our Synthesia guide explains [how dubbing and 1-Click Translation differ](/articles/synthesia-video-translation), step by step. Two limits shape the workflow. Dubbing translates spoken audio only, not titles or burned-in captions. And the Review transcript step, where you correct the transcript before the dub, plus a custom glossary, are Enterprise features. On the self-serve plans the dub runs directly, and you proofread afterward. **Who this fits:** an L&D or HR team, a sales team, anyone whose speaker should still sound like themselves in Spanish or German. ## For creators: AI video dubbing of a finished cut InVideo AI approaches the job from the editing side. Its docs describe a chain much like the five parts above, run inside the editor on a cut you have already finished rather than as a separate upload. The agent replaces the audio for each language but keeps the original track, muted, so you can always go back to it. ### InVideo AI — dub and caption files in one pass InVideo AI says its Editor translates and dubs a finished cut with lip sync built in: the agent transcribes, translates, re-voices with text to speech or a consented clone and re-syncs lips, one branch per language. It can also write SRT or VTT caption files. 1. Type a translate command in Magic Box 2. Switch captions to the new language 3. Export the video and the caption file - Where it stops: Text burned into the footage is not translated; voice cloning needs the speaker's consent, and celebrities or politicians cannot be cloned. - [Voices for your dubs](https://professionalstoolkit.com/articles/invideo-ai-voice-cloning) · [InVideo AI](https://professionalstoolkit.com/tools/invideo-ai) A quicker classic route exists too. You type a command such as translate video to Spanish in Magic Box, then switch the captions to that language. The agent can write SRT or VTT caption files next to the video, so one pass gives you both a dub and subtitles. If you want the dub in your own voice, InVideo AI's [voice cloning for dubbing](/articles/invideo-ai-voice-cloning) needs the speaker's explicit consent in a separate step, and celebrities and politicians cannot be cloned. Two limits apply. Text burned into the source footage is not translated. And dubbing on its own does not change lip movement, so pick the lip-sync step when a face is on camera. Higgsfield sits nearby but covers less of the chain in a documented way. The re-voicing and the lip re-sync live in two different parts of the product, Higgsfield Audio and Lipsync Studio, so you run them as separate passes rather than one. ### Higgsfield — re-voicing and lip sync, as separate passes Higgsfield Audio's Translate tool re-voices content in another language, and Lipsync Studio re-syncs a face to the new audio with a choice of lip-sync models. - Where it stops: Voice cloning is for consented voices only; works in the browser only. - Plan: Lip-sync models: Starter gets one, the rest start at Plus - [Higgsfield](https://professionalstoolkit.com/tools/higgsfield) > ⚠ **On-screen text stays untranslated:** Synthesia's AI Dubbing and InVideo AI both translate speech, not text burned into the footage. Rebuild titles and captions separately, or plan for it before you dub. ## When you already have the translated audio: lip sync tools Some readers already have the hard part done. A translator wrote the script, a voice actor or a text-to-speech tool recorded it, and now the mouth on screen needs to match. Three tools in our catalog cover pieces of this end of the chain, though none of them is a dedicated video translator. ### Kling AI: put new audio on a human face Kling AI's Lip Sync is the narrowest tool on this page: it starts at part 4 of the chain and assumes parts 1 to 3 are already done. Besides a spoken voiceover it also accepts a singing file, so a translated song can be matched the same way. Our guide on [how to use Kling AI](/articles/how-to-use-kling-ai) walks through Lip Sync with the rest of the app. ### Kling AI — matches lips to audio you bring Lip Sync puts your translated voiceover or text-to-speech onto an existing video of a human character, so the mouth matches the new language. - Where it stops: Kling does not translate or replace speech by itself; the full face must be visible, and animal characters are not supported. - Plan: Paid feature - [Lip Sync, step by step](https://professionalstoolkit.com/articles/how-to-use-kling-ai) · [Kling AI](https://professionalstoolkit.com/tools/kling-ai) ### Luma AI and Runway: build it as a workflow Of these two, Luma AI comes closer to a full translation, because a single Agent request reaches parts 2, 3 and 4 of the chain at once. ### Luma AI — an agent prompt in place of a translator Luma describes localizing a finished video in one Agent prompt: translate the script, generate a new voiceover, then lip sync the character. - Where it stops: An agent workflow, not a named translation tool; voice replication only for authorized, consent-driven uses. - Plan: Plus and up - [Luma AI](https://professionalstoolkit.com/tools/luma-ai) Runway covers only the voice link. Its node is a building block you wire into a larger workflow, with the transcript review and the on-screen mouth left to you. ### Runway — voice swap only, built as a workflow A Voice Dubbing node in Workflows converts speech to speech in another language, which you can chain into a larger workflow. - Where it stops: No end-to-end video translator; the old Lip Sync tool was deprecated May 27, 2026. - [Runway](https://professionalstoolkit.com/tools/runway) These fit people already working inside those tools. Starting there just to translate one video is the long way around. ## AI dubbing free: start on YouTube, then add a platform The most useful combination costs nothing for step one. If your video lives on YouTube, YouTube Studio can generate auto-dubbed audio tracks, and viewers can switch between the original and the dubs. Eligibility has rules: videos over 120 minutes, music-only videos, speech that is too fast and videos with copyrighted content are excluded. You can ask to review dubs before they publish, but you cannot edit an automatic dub [1]. Set the original language correctly; a wrong one produces mistranslated dubs. That is the threshold. **When you need to fix a line**, use the dub outside YouTube or keep the speaker's voice in a cloned form, the free route stops. Add Synthesia or InVideo AI at that point. Our step-by-step guide on [how to translate a video](/articles/how-to-translate-a-video) covers the free route in full. A second combination splits the chain between people and tools. A human translator reviews the script. A dubbing platform voices it. A lip-sync tool such as Kling AI fixes the mouth on the shots where a face is close to camera. This costs more effort but gives the most control over wording. > 💡 **Write scripts that travel:** Plain sentences without idioms or slang translate and dub more cleanly. Leave room in text boxes, since translated text often runs longer. ## How to choose an AI dubbing platform Skip rankings and answer four questions about your video. - **Is the speaker a real person who should keep their voice?** Look at Synthesia's AI Dubbing or InVideo AI's cloned voices. Get consent first. - **Was the video made in Synthesia?** 1-Click Translation also translates on-screen text, and it is an Enterprise feature. - **Is it a creator cut that needs captions too?** InVideo AI gives a dub and SRT or VTT files in one pass. - **Do you already have the translated audio?** Use Kling AI's Lip Sync, or Luma AI's agent if you already work there. Two more checks before you commit. Where will the video play? A YouTube-only video can start with free auto dubbing. And how much on-screen text is there? Heavy text means a Synthesia-made video with 1-Click Translation, or rebuilding the titles by hand in an editor. Google Flow is not an option for this job: it does not translate or dub finished videos. Whatever you pick, have a fluent speaker watch every language version end to end. Spot checks miss the line where a product name was mangled. ## FAQ **Is there an AI dubbing tool for free?** YouTube Studio's automatic dubbing is free for eligible channels, but you cannot edit an automatic dub. Synthesia lists dubbing on its free Basic plan, with watermarked output and no MP4 download. **Do I need permission to clone a speaker's voice for a dub?** Often, yes. InVideo AI requires the speaker's explicit consent in a separate step and Higgsfield clones consented voices only; Synthesia's dubbing does not ask for speaker consent but requires that you hold the rights to the video. This is not legal advice. **Does AI video dubbing always include lip sync?** No. Dubbing replaces the voice; lip sync is a separate step that changes mouth movement. In Synthesia it is an option in the dub that uses more credits, and in InVideo AI it runs where a mouth shows. **Can I edit an AI dub after it is made?** Not on YouTube: you cannot edit an automatic dub, but if the dubs were mistranslated you can correct the original video language and YouTube generates them again. In Synthesia, the Review transcript step, where you correct the transcript before the dub, is an Enterprise feature; on the self-serve plans you proofread the finished dub. ## Which links of the chain your video needs Translating a video well means running a chain, not pressing a button: clean transcript, reviewed translation, the right voice, lip sync only where a face shows, and a plan for on-screen text. Synthesia covers the chain for business videos with a cloned speaker voice. InVideo AI covers it for creators who also want caption files. Kling AI handles the lip-sync end when you bring the audio, and Luma AI and Runway cover parts of the chain for people already working inside them. Start free on YouTube if that is where the video lives, and move to a platform once you need to edit the dub. ## Sources [1] YouTube Help — https://support.google.com/youtube/answer/15569972 (Nov 2026)