A valid visa is required for travel to Tanzania. A passport with a minimum validity of 6 months prior to expiry is required. A single-entry visa is valid for 3 months from the date of issue.
Although it is possible to buy a tourist visa upon arrival at the airports of Kilimanjaro, Dar es Salaam and Zanzibar, we recommend that you apply for a visa in your home country prior to your trip.
You can do this online at: https://visa.immigration.go.tz, for US$50. (For U.S. Citizens, the cost is US$100 for a multiple entry visa)
Don't leave it last minute, latest two weeks before arrival in Tanzania so you are sure you give them enough time to process your online application.