Cheep is a free Chrome add-on designed to enhance your flight booking process by providing valuable cost data. It overlays cost per mile information on Google Flights searches, allowing users to identify the best fares quickly. A cost per mile under 6 cents is considered optimal, making it easier for travelers to determine whether to book a flight or wait for better prices.

The tool is particularly useful for nomadic travelers who prioritize cost over specific destinations. For popular routes, Cheep uses extensive analysis of over 1 million fares across more than 200 destinations, suggesting that fares should ideally be under 11 cents per mile. This data-driven approach helps users make informed decisions on when to purchase their flights based on real-time pricing trends.