There are some caveats to this feature. First, they don't tend to alert you instantaneously, but rather on a bit of a delay. So, it’s unlikely a flight alert would catch a Mistake Fare—when airlines accidentally discount a flight far below what they intended—and alert you in time to be able to book it before it disappears.
Second, flight alerts really only work if you have a set destination and dates, and you can only set an alert for a specific trip. You can’t, for example, set an alert for all of Europe for the month of September. So, if you’re just looking to snag the cheapest fare and your dates are very flexible, there are better ways to get alerted of a great deal (hint: join Scott’s Cheap Flights).
However, if you’re interested in following a specific trip (with set departure and destination and set dates), setting up alerts on Google Flights is a great way to keep track of the prices. If you set up the alerts far in advance, you can get a feel for the average price, and when the price drops, you can recognize a good deal and purchase it.
Here’s how to set Google Flight alerts so you can track the price of an upcoming flight.
1. Enter your travel info to search for a flight.
Create a flight search as you normally would, by entering your departure and destination airports (you can input up to 7 airports) and your travel dates, and then hit “Search.”
2. Click the button to track prices for a specific route.
On the left hand side of the results page you’ll see a button to “Track prices” (which we’ve highlighted here). Turn it on to track the prices for all flight options for that route on your selected dates. This way, if the price drops at all, no matter what airline or specific flight, you’ll find out.
3. Or, go to the results and click to track prices for a specific flight.
If you know you want to fly on a specific flight, input your airports and dates as usual and click “Search.” Then, select the specific flights you want to take by clicking on them as though you were going to book them.
Once you get to the page that sends you to the airlines to book, you can click the button (this time it’s on the right hand side) to track prices for this specific itinerary. Here’s an example of a flight that’s codeshared among Delta, Virgin Atlantic, and Air France. In this case, if a flight on American were to suddenly get cheaper, you wouldn’t be notified; you’ll only receive alerts for this specific itinerary.
4. Log in or create a Gmail account.
You’ll need to be logged in with a Google account to set up tracking and receive notifications by email; if you aren’t logged in, you’ll be prompted to do so (or to create a Gmail account if you don’t have one).
5. Check your email.
When you receive a price alert by email, it’ll show the most recent price and the new price for the route or specific flights you’ve tracked, like this example email.
Remember, there are some limitations to relying on Google Flights alerts to find the best deals. While it’s helpful if you have a specific flight or a set route with inflexible dates, if you’re more flexible, you’d need to set dozens of alerts to capture all the possibilities.
For example, if you’re looking to go to the UK at any time in September, it would require dozens of date combinations to cover all your bases. And you’d could still miss out if there’s an incredible deal to a nearby city, like Paris or Amsterdam, that would be a quick (and cheap) local flight to London.