Why Is The Air Canada Website So Slow? Here Are The Reasons

Air Canada is the flagship carrier from Canada with its headquarters in Montreal. The official website is located at

A speed report from Lighthouse paints a rather grim picture and scores Air Canada website 9.7 seconds on the speed index (SI), and 30 on Performance.

There are many reasons why the Air Canada website is so slow. This includes:

  • Bloated JavaScript files
  • Unnecessarily large image files
  • Render-blocking resources
  • Large DOM size
  • Ineffective Caching Policy

Let’s look at each of these reasons and identify potential ways that Air Canada can make their website load faster.

But before we do that, a quick word about our website - we are a free email alert service that sends out notification any time your website is loading very slowly (often due to heavy traffic, or poor scripts). If you have a website, consider setting up an alert so that you can fix issues before they become major. 

Bloated JavaScript files

Air Canada uses a lot of JavaScript to run the website. However, loading them all from one source could slow up the performance of the website. Air Canada can avoid this by splitting the code into smaller files. This way, you only load files that are necessary.

The Air Canada website can be as much as 4.87 seconds faster by adopting this technique.

Unnecessarily large image files

Another common problem that users face – especially when they access the website during their commute to work or office – is unnecessarily large image files that are not optimized for the mobile phone. Not everyone has access to WiFi at all times. Loading oversized product images is unnecessary.

According to the Lighthouse estimate, Air Canada website homepage can load 0.64 seconds faster if it made all the images more cellular-data-friendly.

Render-blocking resources

There are scripts on the Air Canada website that need to run first before they let the rest of the code be executed. The render-blocking resources issue can shave off around 0.45 seconds from the loading time for the Air Canada website.

How do you avoid this? If the script is not critical, avoid having it in the <head> tag of your HTML code. But if you do need to have it there for some reason, make sure to include the defer or async attribute so that they do not block the loading of other resources.

Large DOM size

The Air Canada website takes close to 14.9 seconds to evaluate all the scripts, parse them, compile, and render them. This can be minimized by minimizing the main-thread work.

They may also look at reducing the number of nodes in the DOM. In simpler terms, you need to make sure that the main HTML code is smaller and has fewer nodes. I have explained this in greater detail in this article about DOMContentLoaded.

Ineffective Caching Policy

A website like Air Canada is made of several components, including a lot of images, and other media files. Caching, or storing these components in your local computer, enables your browser to load the website much faster when you come back a second or third time.

With Air Canada however, the cache for most media files clear is deleted every 60 minutes. This means that the website is loaded completely from scratch any time you visit after 60 minutes. Enabling a longer cache period could make loading pages faster and more user-friendly.

1 thought on “Why Is The Air Canada Website So Slow? Here Are The Reasons”

  1. I just attempted to purchase a ticket from both the Air Canada website and the Air Canada app – I got this message: “ERROR AT FOP CREATION: SOME FOPS ARE DEFECTIVE, PAYMENT FAILED – PLEASE CONTACT AIRLINE” Air Canada has had a persistent, embarrassing problem with how they accept payments. On this last attempt, the site wouldn’t even allow me to enter my CVV – there was no place for it, unless I selected that I wanted to pay extra for “carbon offsets” – and then the CVV box would appear. But then the payment error mentioned above appeared as we;;. A terrible, terrible buggy website and app. I had to book my ticket for the same flight on United Airlines (their partner airline). Air Canada’s UX is the WORST I’ve ever encountered for an airline site and app.

    They’re now running a “BETA” version of the “updated site” for Aeroplan members – only once the user selects the flight corridors

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