There are conflicting dates as to when they truly won independence. Some say 1945, others say they were recognized as free 1949. On the other hand, more efforts were made in 1950 for Indonesia to be handed over full authority from the Dutch.
1949: The Dutch finally recognized the sovereignty of Indonesia December 27.
1950: Officially took on "post-colonial nation"
1945: The start of the Indonesian National Revolution. This was a deceleration, which is why some people associate the year with their independence.