On the website:
After you enter your flight search, you will see a price graph in the upper right-hand corner of the search results screen, which shows the cost of that route on other dates. Note that filters are not taken into account for these prices.
You can also hover over a particular flight result to see if there is a price history for that specific itinerary on that airline:
Lastly, you can see our predictions about a particular search and track the price. You must be logged in to track. We will also show if the price fluctuated recently and predict how it may fluctuate in the near future. Please note that our prediction is not a guarantee as we have no influence on flight prices.
On iOS devices:
The price graph will appear at the bottom of the screen when you search by dates on the calendar and when viewing the trip details of a specific flight.
Android devices:
The price graph will appear at the bottom of the screen when you search by dates on the calendar and when viewing the trip details of a specific flight.