Both options get you from SCL to central Santiago. The question is which suits your situation better.
Official airport taxis
Santiago airport has two main taxi services — Transvip and Transaereo — that operate from counters inside the arrivals hall. You pay a fixed rate at the booth before heading to the vehicle. They offer shared vans (cheaper, multiple stops) and private cars (direct, more expensive).
The advantages: no pre-booking needed, you pay when you arrive, and the fixed rate eliminates meter anxiety. The disadvantages: during peak arrival times, there can be a queue at the counter, and shared vans make multiple stops which can double your journey time.
A private taxi to central Santiago (Providencia, Las Condes, Santiago Centro) runs roughly 20,000-30,000 CLP ($20-30 USD). A shared van is 8,000-12,000 CLP per person.
Pre-booked private transfer
A driver is waiting for you in arrivals with a name sign. You walk out, get in the car, and go directly to your address. The price is agreed in advance — typically $25-50 USD to central Santiago depending on the vehicle.
The advantages: certainty. You know someone is there regardless of what time you land, how delayed your flight is, or how crowded the arrivals hall is. The driver can track your flight and adjust for delays. No queue, no counter, no negotiation.
The disadvantage: it costs slightly more than an official taxi and requires booking ahead.
When each makes sense
The taxi works well when: You arrive during normal hours, you are flexible about shared vs. private, you speak enough Spanish to communicate if needed, and you are comfortable navigating the booth system at the airport.
The transfer makes more sense when: You arrive late at night, you are traveling with family or heavy luggage, you want a child seat (which taxis do not have), your accommodation is in an area that is hard to find, or you simply do not want to think about logistics after a long flight.
The honest cost comparison
For a solo traveler heading to a central hotel during daytime hours, the taxi is cheaper and perfectly fine. For a family of four with bags, the transfer becomes competitive on a per-person basis while being considerably more convenient. For late-night arrivals, the transfer is arguably better value once you factor in potential surge pricing on ride-hailing apps and the peace of mind of guaranteed pickup.
What about ride-hailing
Uber, Cabify, and DiDi are available at SCL and often cheaper than both taxis and transfers. The trade-off is uncertain pickup logistics — drivers may struggle to reach the terminal, communication can require Spanish, and surge pricing during peak times erases the cost advantage. It is a good option for the tech-savvy traveler with a local SIM card, but adds a layer of uncertainty that taxis and transfers avoid.