Flight price alerts: how to track flight prices and know when to book

The short answer: let the fare come to you

A flight price alert is a saved search that keeps running after you close the page. You choose a route, and sometimes dates, and the service checks fares regularly and emails you when the price changes or falls below a figure you choose. It’s the simplest way to track flight prices without searching every day, and it costs nothing.

Alerts work best when you know roughly where you want to go and have some time before you need to book. They won’t make a fare cheaper, but they make sure you see a drop when it happens, which matters because fares can change often before departure.

How the main price alert tools work

Each tool works slightly differently. This summary is based on each service’s own help pages, plus our own alerts.

Our view is that the type of alert matters more than the brand. A fixed-dates alert suits a trip you’ve already planned around, such as a wedding or a school holiday. A route alert with no fixed dates, or a target price, suits a trip you can move: you hear about the cheap weeks and fit the trip around them. If you don’t mind where you go, our deals page is a quicker way to see what’s cheap from your city right now.

How to set up a price alert that works

These steps are our own method. The aim is an alert that only emails you when the price is genuinely worth acting on.

1. 1Open the fare calendar for your route and look at the cheapest fares found over the coming months
2. 2Pick a target price a little below the typical fare for your dates: low enough to be a real saving, not so low it never arrives
3. 3Create the alert with your email address and confirm it from the link we send
4. 4Set a second alert on Google Flights or Skyscanner if you want to compare, especially for exact dates
5. 5When an alert arrives, check the full price with bags and the flight times before you book

When to start tracking

Start early enough to see a few price changes before you need to book. Google’s 2026 analysis of Google Flights data for US departures found the lowest average fares about 39 days before departure for domestic trips and about 89 days before for international ones. For a long-haul trip such as London to New York or Los Angeles to Tokyo, that means setting your alert several months ahead. Our guide to when to book international flights covers the booking window in more detail.

For peak dates, start even earlier. Fares for school holidays and Christmas rarely fall late, as we explain in are last-minute flights cheaper?.

What to do when the alert arrives

Act on it the same day if the price suits you. A low fare usually means only a few seats are left at that price, and the next email may show it has gone back up. If you’re booking from the US, the Department of Transportation’s 24-hour rule gives you a safety net: airlines must let you cancel for a full refund within 24 hours of booking, as long as you booked at least seven days before departure. That means you can book a good fare straight away and still change your mind the next day.

If you’ve booked and the price then drops, don’t assume you can claim the difference. Most cheap fares can’t be changed for free; check your fare rules, and our guide to the 24-hour cancellation rule explains when cancelling and rebooking is possible.

• Check the alert matches your dates, airports and number of travellers
• Add bags and seats to see the total, not just the fare
• Check entry rules and travel permits for your destination
• Turn the alert off once you’ve booked, using the link in the email

Our verdict

Price alerts are the easiest way to stop overpaying without spending your evenings refreshing search results. Set one as soon as you know where you want to go, pick a realistic target price, and book when it lands. Combine it with flexible dates, using our guide to the cheapest day to fly, and you’ll catch most of the savings there are. For more ways to cut the cost, see how to find cheap flights.

Questions people ask