Both taxis and private transfers get you from Mehrabad to central Tehran in roughly the same time. The difference comes down to predictability, comfort, and how familiar you are with Tehran.
The taxi experience at Mehrabad
Outside the arrivals exit, you will find a taxi stand with official airport taxis. These are usually Iran Khodro Samand or Peugeot 405 sedans. The vehicles are functional but older compared to what you might expect from European or Gulf airports. Drivers speak limited English in most cases.
The process involves walking up, stating your destination, and either agreeing on a price or using the meter. Many drivers prefer a flat fare over the meter. The price negotiation is brief but can be frustrating if you do not know what the going rate is. Payment is in cash Rial only.
There are also unofficial taxi drivers who approach you inside the terminal. These are not regulated, and while many are perfectly fine, prices tend to be higher and there is no accountability if something goes wrong.
The private transfer experience
A pre-booked transfer means a driver is waiting specifically for you, usually holding a sign with your name. The vehicle is typically a newer model in better condition than the average taxi. The driver knows your destination in advance, the price is fixed and often paid online, and there is no negotiation at the curb.
For someone visiting Tehran for the first time, this removes the two biggest stress points: the language barrier and the currency confusion.
Where taxis win
Taxis are cheaper by a modest margin, roughly 30 to 40 percent less than a private transfer. They are available immediately with no advance planning. If you speak some Farsi or have traveled in Iran before, the taxi is a perfectly reasonable choice. The ride-hailing apps Snapp and Tapsi are even cheaper than airport taxis if you have an Iranian SIM.
Where private transfers win
Private transfers win on certainty. You know the price before you land. You know someone is waiting for you. You do not need Iranian cash in hand. This matters most when you are arriving late at night, traveling with family, or visiting for the first time. The vehicle quality is also better, which matters on longer rides to northern Tehran.
The practical verdict
If you are an experienced Iran traveler with a local SIM card, use Snapp or Tapsi for the best price. If you are comfortable with a bit of negotiation and have Rial cash, the official taxi stand works well. If you want the smoothest possible arrival, especially on your first visit, a pre-booked transfer is worth the premium. The cost difference is small in absolute terms, usually around 5 to 10 USD.