If you have ever run a website speed test before 2014, you may have come across a suggestion to avoid AlphaImageLoader filter, but what does that even mean? Well, besides being a very confusing combination of words to read, AlphaImageLoader has to do with the browser not supporting images (.pngs) with transparent backgrounds, specifically with the Internet Explorer 6 browser. Internet Explorer 6 was retired in 2014, so the issue is not relevant today, but at the time it was implemented to fix transparent PNG issues, but sometimes caused the browser to stall and lock up completely. Not the best solution when it comes to providing a great user experience at the time. So, at the time, if you came across the AlphaImageLoader filter, the best approach was to ignore it completely, and work with a different PNG version, if possible. Thankfully, with modern browsers and CMS solutions, you should not have to deal with issues like this anymore.
Avoid AlphaImageLoader Filter
What is AlphaImageLoader?
Lighthouse is an open-source tool that is used to run an audit against your web pages and provides scores and suggestions for improving page performance, accessibility, SEO, and more.
PageSpeed Insights is a tool created by Google that reports on the performance of a page on both mobile and desktop devices, and provides suggestions on how that page may be improved.