Skyscanner vs Kayak vs Google Flights — which aggregator finds the cheapest fare?

Google Flights pulls the broadest set of airline-direct + OTA sources of the three and renders a date grid faster than anyone else. It is the strongest for scanning flexible dates across many carriers in one view. It tends to default to airline-direct booking links, which limits exposure to OTA-only discounted fares but improves the chance the headline price is the real checkout price.

Skyscanner skews heavier on European low-cost carriers and international partners, especially Asia-LCC routes that the other two aggregators do not always surface cleanly. On intra-European and Asia-LCC routings, Skyscanner frequently shows fares 10-25% below what Google and Kayak return on the same itinerary. The catch: many Skyscanner OTA partners add service fees that surface only at checkout.

Kayak has the deepest US-heavy OTA partnerships and frequently shows promo-driven OTA fares on US-domestic routes that beat airline-direct pricing by $20-$80. Its pricing on opaque (no-name) booking partners is often the cheapest headline, but the fare-class and rebooking rules behind those fares are typically the strictest in the market.

Use Google Flights as the first stop for US domestic and transatlantic published fares — its breadth, date-grid speed, and tendency to default to airline-direct booking make it the safest general-purpose aggregator. It is the right tool for “what week of October is cheapest for a Paris trip?”

Use Skyscanner for intra-European LCC routes (Ryanair, easyJet, Wizz, Vueling) and Asia-LCC routes (AirAsia, Scoot, Jetstar Asia) — it surfaces those carriers’ fares more reliably than the others. Use Kayak when shopping US-domestic and looking for OTA-discounted headline fares — but check the fare rules before paying because the cheapest headline is often the strictest fare class.

For a long list of common itineraries, calling reliably beats all three aggregators on the all-in fare — because aggregators by design cannot expose private contract rates, phone-exclusive promo codes, or alliance-partner fare buckets that live offline. The aggregator quote is the published-fare ceiling; calling finds the floor.

• Multi-city — agent-built alliance multi-stop products usually beat the cheapest aggregator quote by 15-30%
• Family international — bundled child fares and seat-together blocking, none of which aggregators surface
• Transpacific business — Z/D/I fare-class inventory below what aggregators query, $1,500+ savings
• Last-minute (within 14 days) — private same-day rates and partner inventory that aggregators do not have
• SAVE30 applied to the all-in agent quote — phone-exclusive, stacks on the private rate, does not appear on any aggregator

The right workflow: use Google Flights for the date grid, cross-check with Skyscanner or Kayak on specific suspicious fares, then call for the complex or expensive trips. On those itineraries, calling after comparing aggregators typically adds another $100-$400 in savings.