Best flight booking sites - and the ones to avoid

Opodo is the worst-rated flight booking site according to a recent survey, despite separate research showing it’s the best at finding bargain airfares. However, choosing cheap fares may not be worth it if you’ll receive poor customer service should your flight get cancelled.

The platform fell well short of Which? members’ expectations of a good flight booking site, gaining a 28% overall customer score. While most competitive in our price checks, the site garnered just two stars out of five in the value-for-money category.

Opodo also scored just one out of five for its customer service. However, no sites, not even top-of-the-table Expedia, were rated favourably in the customer service category, with the highest rating across all sites just two stars.

Members scored flight booking sites across various other categories, too, including how well each website functions and how transparent it is with fees. But to determine the best overall, we asked customers to tell us how satisfied they were with their experience and how likely they were to recommend it - which secured Expedia the top spot. 

Alongside our survey, we checked 30 different fares across flight booking sites - where you pay for the flight on the site directly - and comparison sites - which trawl the web and aggregate prices but ultimately send you to an airline or booking site to make the final transaction. We recorded prices across nine sites in total.

Expedia failed to find the best fare on a single occasion, while Opodo found the cheapest 11 times in 30.

Read on for our reviews of all flight booking sites, as well as why Expedia struggled to source cheap fares.

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Best flight booking sites - and the worst-rated

Our snapshot pricing research

Best flight booking site: Expedia

Customer score: 70%

Expedia does a lot right according to members; its site is reasonably functional - meaning it’s easy to use and navigate - and tends to be transparent over any additional fees. It landed three stars out of five in these categories. It could explain why the overall customer rating (70%) is head and shoulders above rivals. However, that doesn’t mean a great deal if it can’t find customers the best airfares. Expedia actually found the most expensive fares on 16 routes in 30. So why does it struggle to uncover cheap flights? Partly because it doesn’t include flights from two of Europe’s largest low-cost airlines, Wizz Air and Ryanair.

Should you book?  Probably not. It’s no good at sourcing the best prices - although you may find tickets with better-rated airlines using the site.

Go to Expedia’s site to find out more 

Worst-rated flight booking site: Opodo

Customer score: 28%

Opodo returned the cheapest airfares more times than any other site – but don’t be lured in. One customer said it offers ‘zero customer service’.  Opodo’s subscription service, Prime, was also a major gripe. Some users unwittingly signed up for it when buying their flights and were later charged. It received a paltry one star for customer service in our survey. 

Should you use it? No. Shocking service.

Go to Opodo’s site to find out more

Other flight booking sites 

• Booking.com: 55% - head to Booking.com to find out more
• Lastminute.com: 40% - head to Lastminute.com to find out more

Should I book with any flight booking site?

Third-party flight booking sites aren’t generally worth the hassle. Booking through them makes things much more complicated if something goes wrong – like a delay or a cancellation, or if you need to amend the booking.

Should I use a flight comparison site?

Comparison sites such as Google Flights, Skyscanner and Kayak are different as you don’t complete the final transaction with them. They are handy when comparing airfares for your route - see our reviews of comparison sites. Use them to find the cheapest airline and then book directly, filtering out prices that lead you to third-party flight booking sites. Then, if anything goes wrong, you know who’s responsible for rebooking your flight or refunding you.

• Compare flights on Google Flights
• Compare flights on Kayak
• Compare flights on Skyscanner

Before securing a flight, read our reviews of the best and worst-rated airlines.

How to get cheap flights

• The sweet spot for finding a fair flight price is six months before travel on average, according to Skyscanner data. 

• Saturday tends to be the priciest day to fly, while Tuesday is often the least expensive - although this varies.

• Be flexible on your dates. Search for flights throughout an entire month using comparison sites such as Skyscanner, Google Flights and Kayak to locate the cheapest outbound and inbound fares.

• Set up a price alert. Flights are priced dynamically, meaning they go up and down depending on demand. An alert will email you when prices change so you can swoop in and get a bargain if they suddenly drop.

 See more tips on how to save on flights and the cheapest days to book and fly.

Our pricing research on flight booking sites

Pricing research was carried out on 3 October 2023. Which? recorded prices of 10 stays and 10 flights one week, six weeks and six months before departure, totalling 30 fares. We checked for each fare on nine booking and comparison sites in total to find which sourced the cheapest price.