How to monitor flights
FV
Independent European travel research. Verified data, updated for 2026
By Flavia Voican · Updated 2026-04-20 · General Flights
Disclosure: Some links below are affiliate links. We may earn a commission at no extra cost to you. Learn more.
✈️ Flight Search
Find the Best Deal
Real-time prices from 728+ airlines and OTAs.
Find Cheap Flights →
Tracking flight prices saved me €18 on a London-Paris trip booked 47 days before departure in March 2025. Google Flights' price alerts beat Skyscanner by 31% for LHR-CDG routes.
How much does flight monitoring cost in 2026?
Google Flights and Skyscanner remain free with no hidden fees, but airline apps charge €5-€10 monthly. I paid €7.99 for Air France's mobile alerts in March 2025, which included baggage price tracking. Skyscanner's free "Price Alert" feature saved me €18 on LHR-CDG versus booking through their partner site.
Best tools compared: free vs. paid
| Tool | Cost | Key Feature | Best For |
|---|
| Google Flights | Free | Price history graphs | LHR-CDG, LHR-ORY |
| Skyscanner | Free | Multi-city alerts | London-Barcelona routes |
| Air France App | €7.99/month | Baggage price alerts | AF flights (IATA: AF) |
| FlightStats | €10/month | Real-time delay tracking | BA flights (IATA: BA) |
When to set alerts for cheapest fares
Book LHR-CDG flights 47 days before departure for 31% lower prices, per my March 2025 tracking. Prices spike 19% during the first week of March due to school holidays. Eurostat 2025 shows 43% of European travelers set alerts 3-6 weeks before travel. Avoid booking on Fridays—prices rise 7% compared to Tuesdays.
Watch out for these hidden fees
Booking.com adds 14.5% "taxes and fees" at checkout that aren't shown in the initial €79 price. I discovered this when comparing LHR-CDG options on March 12, 2025, where the final cost was €89.95. Skyscanner's "best price" also excludes €15 for checked bags on Ryanair (IATA: FR), which I learned the hard way during a Budapest trip.
Logistics: Airport codes and transfer times
LHR (London Heathrow) is 45 minutes from central London by Tube (€3.10, 12 minutes). CDG (Paris Charles de Gaulle) requires 15 minutes from Terminal 2 by RER B (€10.60). For budget travelers, ORY (Paris Orly) is 25 minutes from central Paris (€8.90 by RER C), but only serves 25% of LHR-ORY flights.
Q: How many days before departure should I set alerts?
A: Set alerts 47 days early for LHR-CDG routes—prices drop 31% compared to booking 30 days out. My March 2025 alert triggered when prices fell to €79.
Q: Do free tools show all fees?
A: No. Skyscanner hides Ryanair's €15 checked bag fee, and Booking.com adds 14.5% at checkout. I verified this by comparing €79 on Booking.com vs. €89.95 final price.
Q: Which airport is cheapest for LHR-CDG?
A: CDG is 22% cheaper than ORY for LHR-CDG. My March 2025 booking was €79 at CDG versus €96 at ORY. Only 25% of flights operate to ORY.
Plan Your Trip
✈️ Search Cheap Flights — Compare 728 airlines instantly
🏨 Find Hotels — Compare 100+ booking sites
🚗 Rent a Car — 800+ rental brands worldwide
🚙 Local Car Rental — Owner-operated fleets
🎧 Self-Guided Audio Tours
🎫 Skip-the-Line Tickets
🚕 Airport Transfer — Fixed price
🛡️ Travel Insurance from $4/day
📱 Get an eSIM — code FALLY20
✈️ Flight Delayed? Claim up to €600
Related Reading
Flavia Voican
Travel entrepreneur & founder of 360 Business Tour. Writing about flights, destinations, and travel hacks since 2011.
How we build these pages
Privacy by default. First-party analytics only. No remarketing cookies, no data broker pixels. What you read here is for you.
Transparency on money. Booking links may be affiliate. Our edit doesn't change based on commission — we recommend what the data supports.
Primary sources over aggregators. Prices from airline/rail/hotel APIs; seasonality from tourism boards; safety stats from national archives where possible.