San Francisco, CA SFO to San Diego, CA SAN flight with United

United Airlines, established in 1926, is a major U.S. airline headquartered in Chicago, Illinois. Operating an extensive domestic and international network, United serves more destinations than any other airline, connecting travelers across six continents. The airline's eight hubs include Chicago–O'Hare, Denver, Houston–Intercontinental, Los Angeles, Newark, San Francisco, Washington–Dulles, and Guam. As a founding member of the Star Alliance, United offers a comprehensive range of services, including regional flights through United Express, catering to both leisure and business travelers. The airline is committed to sustainability, investing in sustainable aviation fuel and innovative technologies to reduce its environmental impact.

American Airlines is one of the largest airlines in the world, connecting travelers to hundreds of destinations across the United States, Latin America, Europe, Asia, and beyond. Operating from major hubs such as Dallas/Fort Worth, Miami, and Charlotte, American offers a wide range of travel options. Passengers can choose from Economy with affordable fares, Premium Economy with extra space, or Business and First Class featuring flat-bed seats, premium dining, and lounge access. With a modern fleet and membership in the oneworld alliance, American Airlines combines global reach with comfort and reliability.

Alaska Airlines, headquartered in SeaTac, Washington, is a major U.S. airline and the fifth-largest in North America by scheduled passengers carried as of 2024. Along with its regional partners, Horizon Air and SkyWest Airlines, Alaska Airlines operates a route network primarily connecting cities along the West Coast of the United States, including Alaska and Hawaii, to over 100 destinations in the contiguous U.S., the Bahamas, Belize, Canada, Costa Rica, Guatemala, and Mexico. The airline is a member of the Oneworld alliance, offering passengers access to a broad global network. Alaska Airlines is known for its customer service and loyalty program, Mileage Plan, and offers First Class, Premium Class, and Main Cabin seating options. The airline's primary hub is Seattle-Tacoma International Airport. In 2024, its parent company, Alaska Air Group, acquired Hawaiian Airlines.

Spirit Airlines is an American ultra-low-cost carrier, headquartered in Dania Beach, Florida, operating scheduled flights throughout the United States, the Caribbean, and Latin America. Known for its distinctive bright yellow planes, Spirit's business model traditionally focuses on offering low base fares by unbundling services, allowing passengers to pay only for the amenities they choose, such as baggage and seat selection. As of August 2024, Spirit is evolving its offerings, introducing new fare tiers like \Go Big,\" \"Go Comfy,\" \"Go Savvy,\" and \"Go,\" which include various bundled perks such as wider seats, extra legroom, priority boarding, and in-flight refreshments. Spirit was the seventh largest passenger carrier in North America as of 2023."