All the files that are published through the use of file release system of OSDN project or chamber are mirrored by the mirror servers which are managed by organizations who cooperate with OSDN's open-source activities. The users who download files from OSDN will receive the files from those mirror sites.
The time consumed in downloading varies according to the mirror site's server performance, geographic location, condition of the network system, and so on. Users can choose, from the download page, the mirror site they prefer for downloading files.
Below is the list of mirrors in operation.
| Logo | Name | Location | Continent |
| Japan Advanced Institute of Science and Technology | Nomi, Japan | Asia |
| Internet Initiative Japan Inc. | Osaka, Japan | Asia |
| GLOBALBASE | Osaka, Japan | Asia |
| RWTH Aachen University | Aachen, NRW, Germany | Europe | |
| CZ.NIC | Czech Republic | Europe |
| GigeNET | Chicago, Illinois, USA | North America |
| Australian Academic and Research Network (AARnet) | New South Wales, Australia | Oceania |
| Grupa Onet.pl S.A. | Krakow, Porland | Europe |