Replace Audio in Video
Swaps only the audio of a video for another audio file. The picture is never rebuilt, so the quality stays exactly as it was, and it is done in moments.
Your files are never uploaded. Everything runs on your device.
How to use
- 1Pick a video fileDrop or click to select MP4 / MOV / MKV / WebM
- 2Pick an audio fileAAC / M4A / MP3 / WAV / FLAC. Drop in a video and its audio is used
- 3Run and saveWhen it finishes, check the preview and save the file
How this tool works
A video file holds the picture and the sound as separate "tracks". This tool pulls the two apart, keeps the picture as it is, swaps in the audio from the file you chose, and packs everything into a new video file. The picture data is never touched, so there is no re-encoding, and the quality stays the same no matter how many times you redo it. That is also why it finishes so quickly: the picture is never rebuilt.
Changing the output format from MP4 to MOV or MKV does not change any of this. Only the container changes, and the picture is copied as it is. If you choose a video file on the audio side, its audio track is pulled out and used.
You want different background music, you re-recorded the narration, you need to swap only the commentary. In cases like these, you no longer have to export the whole video again from an editor.
Things to know
- If the original video has subtitle tracks, they are not carried into the output and are lost, whatever the output format.
- If the original video has transparency (an alpha channel), the transparent areas are filled in, usually with black, when you output MP4 or MOV. Choose MKV or WebM to keep it.
- Audio may be converted to match the output format: AAC for MP4, MOV, and MKV, and Opus for WebM. Audio that is already in that format is left as it is.
- Surround audio with three or more channels cannot be converted. It can be kept only if it is already AAC.
- Some output formats are unavailable depending on the video codec.
- The length follows the video. Longer audio is trimmed at the end, and shorter audio is followed by silence.
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