Have you found, downloaded or received an M21 file, but don't know which software program is required to open it?
Before attempting to open an M21 file, you'll need to determine what kind of file you are dealing with and whether it is even possible to open or view the file format.
Answer: Files which are given the .M21 extension are known as MPEG-21 files, however other file types may also use this extension. If you are aware of any additional file formats that use the M21 extension, please let us know.How to open a M21 file:
The best way to open an M21 video file is to simply double-click it and let the default assoisated application open the file. If you are unable to open the file this way, it may be because you do not have the correct application associated with the extension to view or edit the M21 file.
This video file format was added to our database by a visitor to this site, but no additional information was provided. We have yet to investigate this file type further, or there was not enough information available at the time to report accurately on the format.
Please check back soon for more information as we are constantly updating our file descriptions based on search frequency.
Tip: Try to open the M21 file using a text-editor such as Notepad, as many file types contain simply contain unformatted plain-text and can viewed correctly using this method.