3Kayak

Kayak has long been a favorite among frequent travelers due to its versatility and extensive filtering capabilities. While it functions similarly to Google Flights, Kayak goes beyond just flights, allowing users to book hotels, car rentals, and vacation packages, making it a one-stop shop for travel planning.
One standout feature of Kayak is its Price Alerts, which notify you when prices for your selected flights drop or rise, helping you book at the most opportune time. Kayak also offers a Price Forecast tool, giving you an estimate of whether prices are likely to increase or decrease, based on historical data.