JetBlue (https://www.jetblue.com/) is an American low-cost airline with headquarters in Long Island City, New York.
A speed report from Lighthouse paints a rather grim picture and scores the JetBlue website 11.5 seconds on the speed index (SI), and 22% on Performance.
There are many reasons why the JetBlue website is so slow. This includes:
- Unnecessarily large image files
- Bloated JavaScript files
- Absence of text compression
- Old Image formats
- Unused CSS files
- Render-blocking resources
- Ineffective Caching Policy
Let’s look at each of these reasons and identify potential ways that JetBlue can make its website load faster.
But before we do that, a quick word about our website CWVIQ.com - 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. Unnecessarily large image files
A lot of images used on the JetBlue website are not optimized for mobile phones. This can lead to slow loading on mobile data, and also high cost. According to the Lighthouse estimate, the JetBlue website homepage can load 4.5 seconds faster if it made all the images more cellular-data-friendly.
Bloated JavaScript files
JetBlue uses a lot of JavaScript to run the website. However, loading them all from one source could slow up the performance of the website. JetBlue can avoid this by splitting the code into smaller files. This way, you only load files that are necessary.
The JetBlue website can be as much as 2.96 seconds faster by adopting this technique.
Absence of text compression
The JetBlue website uses a lot of text files – including JavaScript. Loading all these different files can take a lot of time. This can be easily avoided if these files were served in a compressed format (like GZip, or Brotli). According to the Lighthouse speed report, JetBlue can save as much as 1.80 seconds during page load just by compressing text files.
Old Image formats
The JetBlue website uses a lot of JPG and PNG files that are considered outdated and heavy for modern web use. Replacing them with WebP and AVIF files can save as much as 1.5 seconds from the page loading time.
Unused CSS files
JetBlue uses CSS files to load the styling elements for the website. However, this file contains a lot of unused scripts that can be slowing down page loading by as much as 0.30 seconds. Code splitting may help avoid this issue.
Render-blocking resources
There are scripts on the JetBlue 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 0.15 seconds from the loading time for the JetBlue 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.
Anand Srinivasan is the founder of CWVIQ, and has been in the internet media space for over 15 years. He has previously served as the AVP of Products and Head of Business at popular media portals. He has worked with several SaaS and enterprise businesses as an external consultant for their SEO marketing campaigns.