On Windows, it opens in Windows Media Player.

There is no need for third-party software. Simply double-clicking the file opens it. MP4 files open in the operating system's default video player. Many consider MP4 to be one of the best video formats available today. It is also a popular video format for streaming over the Internet, such as on YouTube. It is compatible with a wide range of devices and operating systems, using a codec to compress file size, resulting in a file that is easy to manage and store. To resolve this issue, try VLC media player.MPEG-4 (MP4) is a container video format that can store multimedia data, usually audio and video. MP4 is a container that contains various kinds of data, so when there is a problem opening the file, it usually means that data in the container (an audio or video codec) is not compatible with the device’s OS. On some devices, particularly mobile, opening this file type can be problematic.

MPEG-4 (MP4) is a container video format that can store multimedia data, usually audio and video. To resolve this issue, try VLC media player. Keep in mind that M4V is a container that holds various kinds of data, so if there is a problem opening the file, it usually means that data in the container (an audio or video codec) is not compatible with the device’s OS. It is also possible to open M4V files in other media players, such as Adobe Premiere Pro, Media Player Classic, and several others. M4V files open on Windows or Mac operating systems, in Apple iTunes for Windows and Apple iTunes for Mac, respectively. While M4V files are very similar to MP4, they are designed for Apple products and Apple usually protects these files with FairPlay DRM. This results in a file that is easy to manage and store. It stores audiovisual and multimedia data into single file and uses a codec to compress file size. M4V is a container video format that is exclusively for Apple products.

Mp4 converter online