Combine video & audio

Good to know

• Everything happens in your browser — your files are never uploaded anywhere.
• The new audio is mixed with the video's existing sound. To replace the sound entirely, use the Remove audio tool first.
• Start together — audio starts at the beginning of the video and stops when it ends or the video ends, whichever comes first.
• End together — audio is delayed so it finishes exactly when the video does. Only shown when audio is shorter than the video.
• The output keeps the video's original format and quality — only the audio track is changed.