To remove unwanted seconds at the start and finish of a recording, open it in QuickTime Player, choose Edit > Trim, and drag the yellow handles inward until the section you want to keep is selected. The area outside the handles is what QuickTime trims away. Review the selection, click Trim, then save your change. Apple documents the same trimming controls for movies and movie clips. Apple’s QuickTime Player guide to trimming

Before you trim: keep a copy if you may need the original

QuickTime’s trim bar selects one continuous section to keep: it can cut from the beginning, the end, or both, but it does not remove a mistake from the middle while joining the surrounding parts. If you might want the untouched recording later, make a duplicate in Finder first and edit the duplicate. That gives you a separate original to return to if you change your mind.

This workflow applies to a recording that opens and plays in QuickTime Player. Find the file in Finder and open it; if another app opens it by default, Control-click the file, choose Open With, then choose QuickTime Player. No project setup is needed for a simple start-and-end trim.

Trim the beginning and end

  1. In QuickTime Player, open the recording you want to edit.
  2. Choose Edit > Trim. You can also use Command-T, Apple’s listed keyboard shortcut for Trim. Apple’s QuickTime Player keyboard shortcuts
  3. In the trimming bar, drag the left yellow handle right to cut off the unwanted beginning. Drag the right yellow handle left to cut off the unwanted ending. Keep the material between the handles; the portions outside them are marked for removal.
  4. Check both boundaries. Click and hold a handle to inspect individual frames, which Apple recommends for more precise edits. Play the selected section to make sure the recording begins and ends where you intend.
  5. Click Trim to apply the selection.

For example, if a screen recording includes a few seconds of desktop setup before the demonstration and an idle pause afterward, move the left handle past the setup and the right handle before the pause. The example describes how to use the controls; it does not imply a particular timecode or result.

Save the trimmed recording

After trimming, choose File > Save or press Command-S. If you duplicated the file before editing, save the trimmed version with a distinct name or in a different location so you can tell it apart from the original. Apple’s guidance for saving a QuickTime recording uses File > Save and lets you enter a name and choose a destination. Apple’s QuickTime Player guide to saving a recording

If you need a different resolution or an audio-only export, use File > Export As and review the available options. Exporting creates a copy in the selected format or resolution; it is a separate step from trimming. QuickTime’s export options depend on the movie, and Apple says it does not export videos as MP4 files. Apple’s QuickTime Player export guide

What QuickTime’s trim controls do not do

The trim bar is for keeping one continuous portion of a movie or clip. It does not provide separate start and end timecode fields in Apple’s documented trimming steps, and it is not a tool for removing an interior section while keeping both sides. To cut something from the middle, Apple documents a different clip workflow: show clips, move the playhead to a cut point, and choose Edit > Split Clip; you can then edit the resulting clips. Apple’s guide to splitting a movie into clips

If the boundary is hard to place, enlarge the QuickTime window and inspect the handle while holding it to see individual frames. If the result is wrong, undo with Command-Z before continuing, or reopen the untouched duplicate. When the beginning and ending both look right, save the trimmed file and play it from start to finish to confirm it contains the intended continuous section.

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