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Flight comparison sites compared
From Skyscanner and Google Flights to Momondo, which one will help you find the cheapest flights by comparing prices across dozens of booking sites?
Some flight comparison sites promise really cheap fares. The catch? Once you click through, the price sometimes goes up.
A comparison site called Jetcost presented us with the cheapest fares most frequently across the 30 journeys we checked, but many of those low prices were from booking sites we had never heard of. Some of those sites had negative reviews from customers about having to pay more for the flight than the price advertised on Jetcost.
That’s why we went behind the prices in our tests. We asked members of the public to complete tasks on each site to see how easy it was to navigate and whether the advertised price increased when they clicked through to actually buy.
Our in-house experts looked at things such as how sites prioritised sponsored listings and whether they included additional fees in the advertised price.
Skyscanner was best for flights, not only because it was the easiest to use, but also for showing booking site user ratings so that customers can avoid poorly rated sites among other things. We've made it our first ever Which? Recommended Provider for comparison sites.
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Flight comparison site ratings
RECOMMENDED PROVIDER | 81% | ||||
| 79% | |||||
| 75% | |||||
| 74% | |||||
| 73% | |||||
| 49% |
Table notes: Star ratings combine user testing results (using five participants), pricing analysis and expert assessment, carried out Oct 2025. Total score = combines weighted star ratings with how likely user testers are to use the site in future. Site functionality = usefulness, ease of use, sorting/filtering options. Booking options = number of results returned and if it offers airline direct options. Cheap rates = how often a site could return the median price or below vs competitors (we checked 30 flight prices). Transparency and accuracy = if prices match reality after clicking through, plus transparency and prominence of sponsored listings/ads. WRPs: score highly and meet strict criteria.
What is Skyscanner like as a flight comparison site?
Overall score: 81%
Incredibly easy to use thanks to ‘really good filters’ and a ‘logical’ interface, Skyscanner was better than competitors. It stood out for displaying reviews of the booking sites it lists, allowing customers to avoid poor providers – a feature offered by no other comparison site we examined. It didn’t provide as many sites to book through as Google Flights during our snapshot checks, but the fares were almost as cheap. Helpfully, it even indicates if the flight you’re looking at is a good price.
Verdict: A really user-friendly site that will help you easily find the best flight for you.
What is Google Flights like as a flight comparison site?
Overall score: 79%
Google Flights found the most options to book with, scoring the full five stars, and that’s probably why it also generally returned cheap prices. Our experts liked the extra features it offered, such as indicating whether the flight fare shown is typical, low, or high for the season. It didn’t do much wrong. But we would like to have seen user-generated reviews of the providers it links you through to, so you can get an idea of the site you might end up booking with.
Verdict: Not as intuitive to use as Skyscanner, but worth using in tandem as it found more booking options in our test.
Compare flights on Google Flights
What is Jetcost like as a flight comparison site?
Overall score: 49%
At first glance, Jetcost won on price, but don’t be tempted. Many of the sites it listed had negative online reviews saying the final fare was higher than the price on Jetcost. We weren’t given an option to book direct with the airline – a huge flaw, as airlines are often cheaper when you add luggage. Jetcost said: ‘Our priority is to make travel comparisons as clear and trustworthy as possible.’ And that it has a ‘strong ongoing commitment to setting a high bar for clarity, usability, and fairness in travel comparison.’
Verdict: We wouldn’t use some sites it links to, and we don’t recommend you do either.
Using flight comparison sites
While an excellent tool for finding the cheapest airline with the best route for you, remember that comparison sites don’t necessarily vet the quality of the websites they suggest you book with. Nor do they always show you the price of booking with the airline direct – something we’ve found is often cheaper, especially once you add on bags and seats. We’d recommend using comparison sites to narrow down your search and then book directly with the airline to avoid any extra hassle.