How to open D21 files
Did your computer fail to open a D21 file? We explain what D21 files are and recommend software that we know can open or convert your D21 files.
What is a D21 file?
The D21 file extension indicates to your device which app can open the file. However, different programs may use the D21 file type for different types of data.
While we do not yet describe the D21 file format and its common uses, we do know which programs are known to open these files, as we receive dozens of suggestions from users like yourself every day about specific file types and which programs they use to open them.
We are continually working on adding more file type descriptions to the site, so if you have information about D21 files that you think will help others, please use the Update Info link below to submit it to us - we'd love to hear from you!
These apps are known to open certain types of D21 files. Since many different programs may use D21 files for different purposes, you may need to try a few of the apps to open your specific D21 file.