This is live pricing from Travelpayouts' aggregation of 40+ booking engines. The $359 fare is the cheapest current round-trip from Seattle (SEA) to PHL on Alaska Airlines flight AS371, departing 2026-09-24 at 21:27 with return on 2026-10-01.

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