In addition to its own software, the Nintendo 3DS is with most and software. Like the DSi, the Nintendo 3DS is incompatible with DS software that requires the use of the port. Nintendo DS and DSi software cannot be played with 3D visuals on the 3DS. The original DS are displayed in a scaled and stretched fashion due to the increased resolution of the 3DS's screens. If the user holds down the START or SELECT buttons upon launching Nintendo DS software, the emulated screens will be displayed in Nintendo DS's native resolution, albeit smaller with black borders. On the Nintendo 3DS XL, this method yields a viewing size for DS games similar to their native sizes (due to the larger screen size of the XL), unlike on the original 3DS models, where the games appear to be shrunk.
Download Play allows users to play local with other Nintendo 3DS systems using only one Game Card. Players must have their systems within wireless range (up to approximately 65 feet) of each other for the guest system to download the necessary data from the host system. Download Play on Nintendo 3DS systems is also , meaning that it is also available for games. Unlike Download Play on Nintendo DS, game data, once downloaded to the guest system, is stored on the system's SD card, no longer requiring a re-download for a future game session. Nintendo 3DS games can only transfer a maximum of 32 of data to other systems while in download play. Other forms of local multiplayer modes require each player to own the software that is currently being used.
The microphone is placed below the touch screen on the Nintendo DS, though its placement on the four different iterations of the Nintendo DS differs depending on the handheld. The microphone can detect sounds and blowing. Some game software can recognize certain words that the player says, such as in .