Tipping on the Hopper app is entirely optional, though the app frequently presents a "Hopper Tip" as a pre-selected or suggested option during the checkout process. This tip does not go to the airline or hotel; it is a voluntary contribution to Hopper to support their research, price prediction technology, and customer service. In 2026, the app often defaults to a small flat fee (usually $1, $5, or $9) on the final payment screen. Many users find this practice controversial as it can feel like a "hidden fee" if not carefully reviewed. You can always opt-out by toggling the tip amount to zero or unselecting the tip box before you "swipe to pay." It is a digital gratuity intended to keep the app's basic notifications free, but it has no impact on the quality of your flight or hotel reservation itself.