About price guarantee on Google Flights – Travel Help

When you select a price-guaranteed booking option on Google Flights, the price guarantee pays you the difference between the flight price at that time and the lowest ticket price for that exact itinerary as seen on Google Flights between then and departure. To get a payout, the price difference must be greater than US$5. You can receive up to US$500 total per Google Account across all eligible …

https://support.google.com/travel/answer/9430556?hl=en-GG