How to set up a flight alert in 4 steps

Setting up a flight alert means describing the flight you would actually board — not just a route and a date. Most alerts fail for one reason: they are too vague. They surface flights you would never have booked, you learn to ignore them, and the day the right one arrives, you no longer read it.

Here is how to set one up properly, in four steps.

Step 1 — Widen the route before you narrow it

The first instinct is to enter one departure airport and one arrival airport. That is almost always too narrow.

Flying out of New York, JFK, LGA and EWR serve the same city with price gaps that regularly exceed $200. Same on the arrival side: Paris means CDG and ORY. An alert covering all three departure airports sees three times the opportunities — for the same setup effort.

Step 2 — Set a budget, not a wish

"As cheap as possible" is not a criterion: every flight is cheaper than something. A budget is a decision threshold — the price above which you do not book, and below which you reach for your card.

Two guides for setting it: start from the route's usual price, not from what you would like to pay. And keep it realistic — an alert set 60% below market never fires, which amounts to having no alert at all.

Step 3 — Describe what would make you turn the flight down

This is the step almost everyone skips, and it is the one that separates a useful alert from an ignored one. Ask the question backwards: at $400, what would still make you say no?

• Layovers: an eleven-hour connection is not the same offer as a nonstop.
• Baggage: a fare with no checked bag is not comparable to one that includes it.
• Departure times: a 5:40 a.m. departure costs a hotel night or a taxi.
• Airlines: the ones you refuse, and the ones where you earn points.

Each of these filters removes noise. That is where trust in the alert is won.

Step 4 — Tune the frequency, not only the content

An alert that writes to you on every $5 move ends up in the "read" pile. An alert that tells you about a real drop, once, gets opened. Prefer a tool that compares the price to the route's history rather than to yesterday's: that is the difference between "this flight went down" and "this flight is genuinely cheap".

The most common mistake

Creating one very broad alert to "see what comes up". It produces volume, never a decision.

Two or three precise alerts — one per real trip you are considering — beat a catch-all every time. If you are still choosing a tool, our comparison of Going, Hopper and Kestrelia covers what each one is built for, and what a flight alert app actually does in the background explains why criteria precision changes everything.

With Kestrelia

Kestrelia is built around the step 3 that other tools gloss over: 31 combinable criteria, several airports per alert, and a comparison against the route's historical price rather than yesterday's. You describe the flight you would take; we only write when it exists.

The free plan includes one active alert — enough to test the method on a real trip before monitoring several.