---
title: "How to dub a video with AI | ToolSugar"
description: "Dub a video into another language with an AI voice timed to the original lines. See the languages, size limits and what the dub replaces."
canonical: https://toolsugar.com/blog/how-to-dub-a-video-with-ai
image: https://toolsugar.com/og.png
---

# Dub a video into another language with an AI voice

Updated 2026-11-09

To dub a video with AI, transcribe the speech, translate each line and read it back in a new voice at the same moment. AI Dubbing does this for one speaker at a time. Speech recognition, translation and the voices all run in your browser, so nothing is uploaded. You download an MP4 and an SRT.

[Open AI Dubbing](https://toolsugar.com/tools/ai-dubbing)

## Dub a video in three steps

Pick a video of one person talking, such as a tutorial, a lesson or a voice-over.

1. Drop a video.
2. Pick the language to dub into, then a voice.
3. Press Dub video, then download the MP4 and an SRT file of the translated lines.

## How the new voice is timed

Each line stays in the slot of the line it replaces. When a translated line is longer, it is sped up between 0.9 and 1.6 times normal speed, and the pitch is kept. A line that still runs past the next one is cut short with a short fade. The result tells you how many lines that touched.

## What the dub replaces

The new voice replaces the whole original track. Music and sound effects are gone, because the tool does not split speech from background sound. One voice reads every line, so an interview with two people will sound like one narrator.

To keep the background, leave the original video as it is and mix the dubbed lines in yourself, using the SRT file as a guide.

## Languages, voices and downloads

You can dub into English, British English, Spanish, French, German, Hindi, Italian and Brazilian Portuguese. Japanese, Chinese, Korean and Arabic show in the list but the button stays off, because no voice is available. Video Translator can still write captions in those languages.

The first run downloads speech recognition of about 77 MB, or 206 MB with WebGPU, a translation model of about 632 MB, and a voice of about 86 MB (20 MB for German). Your browser keeps them. Translation is a small model and can slip, so check the SRT.

## Questions

### How big can the video be?

Up to 500 MB for H.264 video, and up to 120 MB for other formats that need encoding. Phones get half of each limit.

### Will the voice match the speaker's lips?

No. The tool times each line to when it was first spoken but does not change the picture, so lip movement will not match.

### What happens when the free limit is reached?

AI Dubbing shares 5 free AI runs with the other AI tools in any rolling 24 hours, with no sign up. When they are used up the page says when the next run opens.

[Open AI Dubbing](https://toolsugar.com/tools/ai-dubbing)

## Related guides

- [How to translate a video](https://toolsugar.com/blog/how-to-translate-a-video)
- [How to add subtitles to a video](https://toolsugar.com/blog/how-to-add-subtitles-to-a-video)
- [How to convert text to speech and save an MP3](https://toolsugar.com/blog/how-to-convert-text-to-speech)
- [How to transcribe audio to text](https://toolsugar.com/blog/how-to-transcribe-audio-to-text)
- [How to remove music from a video](https://toolsugar.com/blog/how-to-remove-music-from-a-video)

## Comparisons

- [ElevenLabs alternative](https://toolsugar.com/alternatives/elevenlabs-alternative)
- [HeyGen alternative](https://toolsugar.com/alternatives/heygen-alternative)