Is 3 days enough for a safari?

Only if you are already in the region and have a very focused target. Otherwise, you spend more time traveling to and from the park than actually viewing wildlife.

Should I visit both Kenya and Tanzania?

Only if you have at least 12 days. Crossing the border by land is time-consuming and often requires changing vehicles, which adds cost and stress.

Planning the Perfect Length for an East Africa Safari

Plan for 7 days to cover two major parks in either Kenya or Tanzania without feeling rushed. If you want to visit both countries or include a beach relaxation period, extend your trip to 12 or 14 days to account for travel time between locations.

Define your wildlife goals. If you want to see the Great Migration, you need at least 4 days in the Serengeti or Masai Mara alone. If you just want a 'Big Five' checklist, 2 days per park is sufficient.
Account for transit time. Do not underestimate travel. Bush planes save time but limit baggage to 15kg in soft-sided bags; driving between parks can take 6–9 hours on bumpy roads.
Schedule a 'buffer' day. International flights into Nairobi or Arusha often arrive late. Add one full day at the start to recover from jet lag and finalize logistics before heading into the bush.
Balance activity and rest. Safaris start at 6:00 AM. After 3 days of constant game drives, you will be exhausted. Plan for an afternoon by the pool or a late start every third day.

Is 3 days enough for a safari?: Only if you are already in the region and have a very focused target. Otherwise, you spend more time traveling to and from the park than actually viewing wildlife.
Should I visit both Kenya and Tanzania?: Only if you have at least 12 days. Crossing the border by land is time-consuming and often requires changing vehicles, which adds cost and stress.