How to Edit an MP4 Video

By Bey Wesley

Updated September 22, 2017

Items you will need

  • PC running Windows XP, Vista or Windows 7

  • or

  • Macintosh running at least OSX 10.2 (Jauguar) and Quicktime 6.

  • MPEG Streamclip

You can edit videos on a home computer.
i video montage image by Oleg Verbitsky from

MP4 or MPEG-4 is a audio/video codec designed by the Motion Picture Experts Group (MPEG) and adapted by the International Streaming Alliance to create a standard video format for web distribution of content. Simply said, MP4 is everywhere. Sadly the two leading entry-level video editors, Microsoft's Movie Maker and Apples' iMovie make editing MP4 a little complicated. Movie Maker cannot edit MP4 without help from a codec converter. While the current version of iMovie does support MP4 editing, anything less than iMovie '08 with an Intel chip cannot. A simple solution is to download Square 5's MPEG Streamclip. It is an excellent way to convert video formats, and it can do some simple editing.

Open MPEG Streamclip. Go to the File menu and select "Open." Navigate to the location of your MP4 file. You can also specify a URL, if the file is hosted on the Internet.

Go to the Edit menu; it will provide you with editorial choices for changing your video. If you would like to shorten the beginning of your video, drag the indicator in your time line to where you would like the video to begin. Go the the Edit menu and choose "Select In."

The dark gray line at the bottom of the screen is now indicating the new length of your video.

Drag the indicator to shorten your video. Similar to shortening the beginning of your video, if you would like to shorten the end of your video, drag the indicator to the point where you'd like the video to end on the right side of your time line. Go to the Edit menu and choose "Select Out." This is called the "Out-point."

Remove a section from the middle of the time line; set an In-Point at the beginning of the section you would like to remove. Set an Out-Point at the end of the section you would like to remove. Go to the Edit menu, select "Out-point."

Go the Edit menu again and select "Delete." That section will be removed from the time line.

Move a section of your video. If you wish to move a section of video and place it elsewhere in your time line, you can use a similar method to deleting video. Using the Edit menu, set an In-Point and an Out-Point. Go to the Edit menu and select "Cut." Scroll to the point in your time line where you want to re-position the selected video. Now go to the Edit menu again and select "Paste."

Save your project; go to the File menu and select "Save." Select MP4 as your output format. Everything between the In-Point and the Out-Point will be saved to your MP4 file


Learn the short-cuts as soon as you can. They will save you a tremendous amount of time, and they are very intuitive (setting an In-Point is "I" and setting an Outpoint is "O").

MPEG Streamclip is primarily a codec converter, the editing it does is very simple. It does not do transitions or filter affects. If you need advanced filters, use MPEG Streamclip to change your MP4 into a format that your native video editor software (assuming you have iMovie or Microsoft Movie Maker) can handle. Add transitions and filters, and then use MPEG Streamclip to convert it back to an MP4.


This is just a guide for some simple MP4 editing. If you want to do the great American film, you should invest in professional-grade video editing software.