Wall Street Journal reporter Takashi Mochizuki went on Twitter to say the game cards for the Nintendo Switch will be 16GB. Mochizuki said..
“Looks like standard capacity of Switch game card at least when console launched would be around 16; enough for one-layer Blu-ray game.”
This rumor is also supported by Nintendo Insider Emily Rogers as she tweeted 16GB is standard, but could have larger sized cards in the future. Stating..
“But again…16GB is the standard size for Game cards…Not the maximum size. No different from DS and 3DS.”