This is live pricing from Travelpayouts' aggregation of 40+ booking engines. The $622 fare is the cheapest current round-trip from San Francisco (SFO) to BOS on Alaska Airlines flight AS1450, departing 2026-05-15 at 07:10 with return on 2026-05-18.

Clicking "Book this flight" opens Kiwi.com with this exact flight pre-filtered — same airline, same dates, same passenger count.