Three Steps to a Dubbed Video
No technical knowledge required. No accounts to create. No files to upload. LinguaDub gets you from recording to publishable dubbed content in minutes.
Record or Import
Record directly in the app or import a video or audio file from your iPhone camera roll. Any content with clear speech works.
AI Dubs Your Voice
Choose your target language. LinguaDub's on-device AI separates, translates, and re-synthesizes your voice — all in the background.
Download and Share
Export the finished dubbed video to your camera roll. Share directly to TikTok, YouTube Shorts, Instagram Reels, or anywhere else.
Inside the AI Pipeline
Under the hood, LinguaDub runs a five-stage AI pipeline entirely on your device. Here is exactly what happens between the moment you tap "Dub" and when you get your finished video.
Audio Source Separation
Your recording enters the Demucs source-separation model — the same architecture used by professional music producers and audio engineers. Demucs decomposes the audio into distinct stems: voice, accompaniment (music), bass, and drums. The voice stem is routed forward while the non-voice stems are preserved intact for final recombination. This step is crucial for clean dubbing results: even recordings made in noisy environments or over music are handled correctly.
Voice Profile Extraction
The isolated voice stem is processed by a neural voice encoder that generates a compact voice embedding — a 256-dimensional vector that mathematically represents your unique vocal characteristics. This embedding captures your pitch range, formant frequencies, speaking rhythm, breathiness, and other acoustic features that make your voice sound uniquely like you. Critically, this embedding is derived from your voice but does not itself constitute raw audio — it is a mathematical abstraction used only during the current session and discarded afterward.
Speech Recognition and Semantic Translation
The clean voice audio is transcribed using an on-device automatic speech recognition model optimized for mobile hardware. Unlike simple word-for-word transliteration, LinguaDub's translation layer performs semantic translation — understanding the intended meaning, idiomatic expressions, and context before generating output in the target language. The translated text is timed to match the natural duration of each spoken segment, ensuring the dubbed speech fits the original video pacing.
Voice-Conditioned Speech Synthesis
The translated text is synthesized into spoken audio using a neural text-to-speech model that accepts your voice embedding as a conditioning input. This is what makes LinguaDub sound different from generic TTS services: rather than synthesizing speech in a neutral or stock voice, the model is guided by your voice profile to produce output that inherits your vocal characteristics. The result is target-language speech that sounds like you — same energy level, similar pitch, and comparable speaking style.
Stem Recombination and Video Export
The dubbed voice audio is mixed back together with the preserved background stems from Step 1 at their original volume levels. Timing is aligned to the original video track. The final audio is muxed with the original video frames to produce a complete dubbed video file in the same format and resolution as the original. The exported file is optimized for direct upload to social media platforms without requiring additional transcoding.
Quality: Before and After LinguaDub
The difference between dubbing with and without advanced audio separation and voice matching is significant. Here is what changes when you use LinguaDub compared to basic dubbing approaches.
Without LinguaDub
Basic Dubbing / Manual Translation
- Generic TTS voice — sounds robotic and impersonal
- Background music bleed-through into dubbed audio
- Literal word-for-word translation sounds unnatural
- Pacing mismatches cause audio to run over video
- Requires uploading files to cloud services
- Costs $22–$50/month for professional tools
With LinguaDub
AI Voice Dubbing with Voice Matching
- Your voice characteristics preserved in output
- Clean audio separation keeps background music intact
- Semantic translation maintains natural phrasing
- Timing adjusted to match original video pacing
- All processing on-device — nothing uploaded
- Free tier available — no subscription required
Output Quality Benchmarks
Self-assessed quality ratings based on internal testing across 50+ recordings in varying environments.
Tips for the Best Dubbing Results
A few simple practices when recording significantly improve the quality of your dubbed output.
Use a consistent speaking pace
Avoid speaking too quickly or with long uneven pauses. A steady, natural pace gives the AI the best audio for voice profile extraction.
Keep background music at a reasonable volume
While Demucs handles separation well, extremely loud background tracks can affect separation quality. Background music at 30–50% of voice volume produces the cleanest results.
Minimize echo and reverb
Recording in a small, furnished room reduces reflections. Heavy reverb can interfere with voice profile extraction. A closet with clothes works surprisingly well.
Speak clearly and enunciate
The on-device speech recognition works best with clear enunciation. Strong accents and mumbled speech are supported but may reduce translation accuracy.
Keep segments under 10 minutes
While longer videos are supported, segmenting long content into natural chapters or sections can improve processing speed and give you more control over individual dubbed clips.
Use your native language for recording
Record in the language you speak most naturally. Trying to speak slowly or unnaturally "for the AI" usually reduces quality — just speak as you normally would.
Frequently Asked Questions
How long does LinguaDub take to process a video?
Processing time depends on video length and your iPhone model. A 60-second clip typically processes in 30–90 seconds on a modern iPhone. Longer videos process in the background while you continue using your device.
What file formats does LinguaDub accept?
LinguaDub accepts MP4, MOV, and M4V video files, as well as MP3, WAV, AAC, and M4A audio files. Most content recorded on an iPhone is automatically compatible without any conversion needed.
Does the quality get worse with longer videos?
No. LinguaDub processes audio in optimally-sized segments internally, so quality remains consistent regardless of video length. The Demucs separation model is applied uniformly across all segments.
Can I dub videos with multiple speakers?
LinguaDub is currently optimized for single-speaker recordings. Multi-speaker dubbing with per-speaker voice preservation is a planned feature for a future update.
What happens to my background music during dubbing?
The Demucs engine separates your voice from background music before dubbing. After your voice is re-synthesized in the target language, the original background music is blended back into the final output at the same volume level — your track stays exactly as it was.
Does LinguaDub work offline?
Yes. Because all processing is on-device, LinguaDub works fully offline after the app is installed. No internet connection is required to record, process, or export dubbed content.