No, you do not need a separate visa for Zanzibar if you already have a valid visa for Tanzania. Zanzibar is a semi-autonomous territory of Tanzania, and the visa you receive for Tanzania also allows you to enter Zanzibar.
If you hold a valid Tanzanian visa, you can freely go to Zanzibar without the requirement for a separate visa or authorization. It's worth mentioning that if you're coming from Tanzania's mainland, you may be requested to present your visa or travel documents upon arrival at Zanzibar's entrance ports. As a result, before visiting Zanzibar, make sure you have the requisite Tanzanian visa.
Currently, tourists from all over the world can apply for a Tanzania visa online. If you are looking for a website to apply for a visa online, the Tanzania Immigration Services website is the best choice. We understand that you require a quick and safe online e-Visa application procedure. Join the hundreds of satisfied and successful clients we've had the pleasure of serving. We wish you a wonderful holiday in Tanzania!