It’s official: Airline websites are slow, but they don’t have to be
Illustration by Jeffrey Phillips
Ben Schwarz
September 14, 2026
In this article
Qatar Airways was voted the world’s best airline in 2025. Its booking site ranks 79th. Cathay Pacific, a five-star carrier, ranks last of all.
A single flight booking is about twenty interactions: origin, destination, dates, passengers, fare class, seat map, bags, extras, then payment.
I used Cathay’s site recently and felt all 1.4 seconds of interaction delay first hand. Click the wrong thing and you wait, and regret, until it resolves. Coupled with slow page loads, you’re in for a lengthy session with lots of waiting.
So if booking a flight has always felt like a slog — it isn’t your imagination.
Airline websites are slow. 95% of them fail Google’s Core Web Vitals on mobile.
Using Airline Website Speed Benchmark data, I studied 111 of the world’s top airlines — pulling real-user Core Web Vitals (CWV) data from the Chrome UX Report, cross referenced with if they passed Google’s site speed ranking assessment, Skytrax service rankings, and the technology stack behind each site.
This study used direct booking engine URLs where available (e.g. book.qantas.com.au not www.qantas.com.au), with the aim of capturing a better understanding of the UX of their core business path.
This avoided capturing metrics for static content pages and FAQs, although in some cases they may be included within the dataset, depending on the site.
Airline reservation systems are notoriously complex, and usually involve third party booking and reservation systems, like Amadeus or Sabre, which power a significant portion of the industry.
Flight and seat availability is often calculated in real-time, and must reflect current availability and pricing. Serving hundreds of millions of passengers globally each year. It’s the perfect storm when it comes to web perf.
Aggregator sites like Google Flights or Kayak don’t offer real-time quotes, so they’re able to use extensive data caching to achieve near-instant results — That’s also why the price you thought you were going to pay is often no-longer available.
With those details aside, let’s get into some observations:
Most sites fail Google’s Core Web Vitals assessment, and in a lot of cases: all three underlying CWV metrics.
On the whole, only 5 websites pass criteria on mobile, among them Frontier and Ryanair, both render quickly and respond to interactions in 175ms or less. Outside of a few bright lights, the results are brutal.
Chrome UX Report field data, August 2026.
Desktops have a marginally better experience compared to mobile devices, but both point to a systemic problem across the industry, not just a few outliers.
Grouping by each metric, pass rates are poor across the board. Only 15% of sites have interactions under 200ms on mobile.
Sorting sites by each Core Web Vitals metric, we can see LCP and INP performance ranged from needs-improvement to poor, while CLS is a wider spread.
Many performance experts have been calling for stricter Core Web Vitals thresholds, as they’re seen as too lenient. The data here shows that even with the current thresholds, airlines are failing to meet them.
The world’s “best” airlines have the slowest websites#
You might assume the most prestigious airlines have the best websites. Data says the opposite. All 10 of the Skytrax top-rated airlines fail Core Web Vitals, and rank poorly on our airline benchmark leaderboard.
Skytrax World Airline Awards 2025 service rank (left) against each airline’s overall benchmark ranking (right). Lines that plunge downward mean poor performance. All ten fail Core Web Vitals on mobile and on desktop.
450M+ passengers flew with the top 10 Skytrax airlines in 2025, most of them faced frustrating and slow experiences when booking flights online.
Qatar Airways, voted the World’s Best Airline for 2025, ranks 79th for combined Core Web Vitals performance.
Cathay Pacific, a five-star carrier, ranks dead last, and has the single slowest site of the lot: a Largest Contentful Paint of 10.6 seconds and Interaction to Next Paint of 1.4 seconds on mobile.
As expected, interactions are worse on mobile. 85% of sites do not respond to user input within 200ms, failing to meet Google’s recommended threshold for a good user experience.
Failure rate of each Core Web Vital, mobile versus desktop. 85% of sites fail INP for mobile.
Picture that in a real booking. One booking is a run of twenty-odd interactions: origin, destination, dates, passengers, fare class, seat map, bags, extras, then payment.
On the worst site of all, Air Arabia, P75 mobile interactions are 1.85 seconds. On desktop, Cathay Pacific is 900ms.
The six slowest airline sites by Interaction to Next Paint, against Google’s 200ms (good) and 500ms (poor) thresholds. On mobile, Air Arabia reaches 1.85s.
The slowest of interactions are seemingly blocked by server responses or other dynamic data that block paint.
Interactions can be mapped directly to elements and scripts, so it’s possible to track slow interactions that most frustrate users.
Calibre’s RUM Slow interactions panel shows the overall worst impacting interactions, so they’re easy to prioritise.
Time to First Byte across all airlines, and the six slowest sites, against Google’s 800ms (good) and 1.8s (poor) thresholds. On mobile, Air India Express reaches 5.5 seconds.
Slow loading pages, layout shifts and delayed interactivity. In most cases, simple optimisations could fix the majority of issues.
Dynamic content is often accompanied with poorly constructed skeleton loading states. One click can lead to a page lockup (INP), which triggers a skeleton loader that disorients the user as the page shifts (CLS), followed by a long delay for content to appear (LCP).
Even if you can’t make the page fast (without significant restructuring), you can stop it from shifting awkwardly.
In some cases, UI elements increase in size, or expand to show more information using sub-standard JavaScript animation from a bygone era.
Many of these custom elements can be replaced with web platform native elements, like <details>, <dialog> or popover , which can be styled with CSS, complete with hardware accelerated animation that can be turned on or off with user-preferences.
Forms are also often low quality due to poor quality custom elements that are awkward to use and less accessible too.
Every interaction, from selecting a date to choosing a seat, requires a round trip to the server to check availability and pricing. Those requests should not block the main thread or paint, but they do.
For a date picker, this can mean that the page feels unresponsive for several seconds, both before and after you interact with it.
Most airlines use third-party booking engines, but two sites running the same engine can feel completely different. I collected the data to prove it.
A handful of booking engine vendors run almost everything: Amadeus is behind about two-thirds of the sites. They have multiple products, like Altéa for the full-service carriers and Navitaire for the low-cost ones.
Sabre runs much of the rest, with a smattering of in-house systems and China’s national TravelSky platform making up the remainder.
Time to First Byte, grouped by the company behind each reservation system. Most vendors carry both fast and slow airlines; the spread within a vendor dwarfs the gap between them.
Ryanair is powered by Amadeus’ Navitaire product, and it’s one of the fastest sites in the benchmark. Cathay Pacific is powered by another Amadeus product, and it’s the slowest by quite a margin.
While real-time data is essential for a booking, and caching has been jokingly coined as one of the hardest problems in computer science, there are many opportunities to cache more aggressively.
HTML responses should either be fully cached, or delivered in under half a second.
Booking engine requests should be asynchronous, and should only include the exact data needed for the interaction.
If a single click can make dozens of requests to the booking engine, you have a problem. If those requests are not asynchronous, there’s one slow lookup, the user waits.
Are Airlines leaving scary amounts of money on the table?#
In a word, yes. Shopify found in a recent study, that stores at 2.5 second LCP convert about 30% lower than stores at 1.5 seconds. One second.
Slow interactions cost too: every 32ms of INP is worth another 1.5% of conversions.
Run the numbers for any large carrier and there’s potentially billions of dollars to optimise, with a B. Cathay took HK$72.5 billion in passenger revenue last year. Reducing 10.2 seconds of LCP to 3 could do wonders for their bottom line, and customer sentiment.
While airlines likely have different market dynamics than general e-commerce, like price, route availability, and loyalty programs, the principles are no doubt the same: a slow website is a liability for customers.
All multi-billion-dollar companies, all with the same problem: a slow website that frustrates customers and leaks revenue. There’s money to be made here.
Every airline is judged by service. The booking site is a passengers first step — and in most cases, the worst part of the journey.
Airlines are a fun case to explore, but the pattern lives anywhere conversion meets marketing: retail, banking and travel all look similar under the bonnet.
Like most performance problems, the solution is to focus on the fundamentals. The first step is to measure, and then to act on the data.
Find the highest-traffic pages and optimise them first.
Audit API calls and third-party scripts, and remove any that are unnecessary.
HTTP Cache is extremely effective for improving performance, and should be used wherever possible.
Data should be fetched asynchronously, and should never block users for more than a few hundred milliseconds.
Poorly implemented skeleton loaders will haunt your dreams. Ensure layouts are stable.
By following these principles, and always focusing on fixing the next worst-performing page or single interaction, you can make a measurable difference to your site’s performance, and the experience of your users. Higher conversion rates will follow.
Frontier Airlines topped our Airline industry benchmark leaderboard with excellent performance on Mobile and Desktop. In the last 9 months they’ve trimmed from 3.29 seconds LCP to 2.60 seconds, while also reducing CLS and TTFB. Big improvements are great, but that doesn’t mean that small improvements landing every couple of weeks aren’t worth it. Small improvements add up, kudos to the team for delivering on that.
In the decade the followed, the Ryanair labs team have had an obvious dedication to continuous improvement when it comes to performance and user-experience.
Finally, Hainan Airlines is the only Skytrax top ten site in our benchmark to rank well for performance.
While the numbers presented in this report are sobering, some airlines are doing it right. Frontier and Ryanair have fast, responsive websites that pass Core Web Vitals and provide a good user experience.
It’s possible to build a fast, responsive airline website, but it requires a focus on performance and user experience, as well as a willingness to continually monitor and improve the site over time. Fixing a big website takes time, the best time to start is now.
Ben is the Founder and CEO of Calibre. He uses his experience in far-reaching Open Source projects and web standards to build tools for a better, more accessible web. Find him on BlueskyMastodon or LinkedIn.
