What is an ASF file? An ASF file is a multimedia file stored in the Advanced Systems Format (ASF), a proprietary video and audio container format. It may store only audio data or video and audio data, along with optional metadata, such as title, author, and bibliographic copyright data. Microsoft developed ASF files primarily for streaming media online.

More Information ASF file open in VideoLAN VLC media player The ASF container format only specifies the structure of how the audio or video streams online, which depends on various factors, such as network bandwidth and server performance. In addition, the ASF format does not specify the codec used to encode the audio or video stored in the ASF container format. While the .asf file extension may be used for media files saved in the ASF format, the .wma and .wmv extensions are more commonly used. If the ASF container format stores audio, it is typically saved as a Windows Media Audio ( .WMA ) file. It is typically saved as a Windows Media Video ( .WMV ) file if it stores video. Audio and video data stored within these files may be compressed using a variety of video codecs.