How we know: Sources are listed at the end. Product behaviour is taken from each service's own help pages; there are no fare statistics in this post.
Manual searching and price alerts answer different questions. A search tells you what a route costs right now, across dates and airports you choose. An alert tells you when a route reaches a price you care about. Use the first to decide your target and the second to wait for it.
What manual searching does well
- Exploring. Google Flights' calendar shows the lowest fare for each day, the price graph shows trends by week or month, and the "Dates" and "Airports" insights surface cheaper nearby dates and alternative airports (Google Flights Help). No alert does this exploration for you.
- Comparing itineraries. Stops, times, cabins, baggage rules, one-way combinations across carriers. This is judgement work.
- Booking right now. If you are within a few weeks of departure, a careful search followed by a booking beats any waiting strategy.
What manual searching misses
- Everything that happens between searches. Fares change continuously. A fare that appears on Tuesday evening and is gone by Thursday is invisible to someone who searches on Saturdays.
- Consistency. People search when they remember to, then stop. The moments a fare drops rarely coincide with the moments you happen to look.
- Your own drift. After a dozen searches most people either book out of fatigue or keep waiting past the point where fares start rising.
What alerts do well
- Watch without attention. KAYAK bundles all active alerts into one daily email and can send real-time alerts on a significant change of roughly 10% (KAYAK Help); Wildly checks your tracked routes every day and notifies you only when the fare reaches your target.
- Enforce a decision. A threshold alert turns "is this a good price?" into a yes/no you answered in advance.
- Cover several routes at once. Three origin airports and two destinations is six searches a day by hand and zero by alert.
What alerts miss
- Anything outside their scope. An alert on JFK–London will not tell you Newark–London is cheaper unless you set that too.
- Judgement about the itinerary. An alert fires on price; whether the cheapest option is a 14-hour connection is for you to check.
- Very short-lived fares. A daily check can miss a fare that lasts three hours. Real-time options narrow the gap but nothing closes it.
The hybrid routine
- Search once, properly. Use the calendar and price graph to find the cheapest realistic dates and airports for your trip. Note the current fare for your best option; the route page shows the current price too, for example JFK to London, LAX to Paris or San Francisco to Tokyo.
- Set alerts on the two or three best candidates with a realistic target below today's fare, and flexible dates on. See setting the right price alert target.
- Stop searching. Check back only when an alert fires, or when you reach the typical booking window for your route type (see when to book flights).
- When an alert fires, do one final manual search to confirm the itinerary and book that day.
Set a price alert after your first search and let the routine run.
FAQ
Can I just use Google Flights tracking instead of a separate alert? Yes, and many people do. Google emails on significant changes; a threshold service is quieter and can text you. Running both costs nothing.
Will searching a lot make prices go up? Fares are set by airline inventory systems, not by your search history. Prices rise between searches because cheaper fare buckets sell out or the airline reprices.
How many alerts should I set? Enough to cover your realistic options (alternate airports, a couple of date windows), few enough that a notification still means something.