In this guide
Detach Audio creates a timeline clip you can move or edit separately; it does not automatically save a standalone audio file or separate speech from music. Mac iMovie can export a project as audio only; check the final mix and timing.
To separate audio from video in iMovie, select the video clip in your movie timeline and choose Detach Audio. On Mac, use Modify → Detach Audio; on iPhone, tap the clip, tap Actions and choose Detach. The soundtrack becomes an editable timeline clip. Detaching does not itself create a separate audio file.
All sounds that were already mixed into the video soundtrack remain together in the detached clip. If you need only a speaker or a music track, see the source-separation section below.
Choose the result you need
| Goal | Starting point | Check |
|---|---|---|
| Edit audio independently in iMovie | Detach the video's audio in the timeline. | Keep the clip aligned if you need it in sync. |
| Save a project soundtrack as a file | Use Mac iMovie's audio-only export. | The saved file reflects the project mix, levels and edits. |
| Save audio from a short original video | Use a supported local video-to-audio converter. | Format, duration and timing of the downloaded audio. |
| Keep only a voice or effect | Find original tracks or test source isolation. | Missing words or effects, bleed and processing artifacts. |
Detach audio in iMovie on Mac
- Open your movie project and select the video clip with audio in the timeline. Keep the original video and project.
- Choose Modify → Detach Audio, or press Option–Command–B. Apple says the soundtrack appears as an audio-only clip attached below the video; see its Mac instructions.
- Select the detached clip to move, trim or adjust it. If you move it away from its original position, check sync at the start and end. Deleting or muting the detached clip removes that sound from the project mix.
- Preview the complete edit and export the desired video or audio. Listen to the saved file, not just the timeline.
Detach audio in iMovie on iPhone
- Open an iMovie movie project and tap the video clip in the timeline.
- Tap Actions → Detach. Apple's iPhone guide says a blue audio clip appears below the video.
- Tap the new audio clip to edit or delete it. If you want the picture and sound to remain synchronized, verify their positions after any trim or move.
- Preview and export the movie. The detached clip is an element in the project; detaching alone does not save a standalone MP3 or WAV.
Export a separate audio file
On Mac, iMovie can export a project or clip as audio only. Choose File → Share → File, then select the audio-only format option in the export dialog. Apple's Mac export guide describes the audio-only option. Check the available format and play the exported file: it represents the project mix, including relevant edits and muted tracks, not necessarily the original source soundtrack.
For a supported short MP4 or MOV, the video-to-audio converter can prepare WAV or MP3 locally without an account. Input is limited to five minutes and 50 MiB, with further browser and output limits. It decodes the source soundtrack rather than the edited iMovie project and does not select among multiple streams. Compare timing with the picture if you plan to reinsert it.
Separate a voice from music or noise
Detaching moves the whole existing soundtrack into a timeline clip; it does not unmix sounds recorded together. First look for a clean microphone recording or original music track. If those are unavailable, the voice isolator can test a supported file. Review quiet words and overlap against the original because isolation may alter speech or leave bleed. AI downloads require an account and credits; the local converter does not perform separation.
When returning processed audio to iMovie, align it to the source, mute any duplicate soundtrack and listen for timing shifts. The audio replacement guide explains checks at both ends of an edit.
Common questions
Does detaching audio remove it from the final video?
Not necessarily. The detached clip remains in the timeline and contributes to the project unless you mute, remove or otherwise change it.
Can iMovie save an MP3 just by detaching a clip?
No. Detaching creates an editable clip in the project. Use an available audio-only export on Mac or a suitable separate converter, and verify the chosen format.
Why is my detached audio out of sync?
Check whether the audio clip was moved or trimmed independently. Return it to the original position and compare a clear sound and picture cue near the beginning and end.