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High Performing Images - A practical approach to image compression on the Akamai Edge

HTTP is ubiquitous. Seems like everything today is being served from the web. We are using smartphones to do everything from answering our doorbells while we are at work to remotely controlling SUV's. All of this, happening on a platform we call the World Wide Web. Websites are delivering richer and more personalized content than ever before, creating user experiences that were never conceived of. This means, more than ever, size matters.
This also means the web site that you have spent so much resources on to engage the user, is now tipping in at a hefty 2MB in size per page and more than 100 HTTP requests. With more than half of your users now connecting from mobile networks the clock is literally ticking as they wait for your page to download. So how do you ensure your website is delivered fast and reliably, while still maintaining a rich brand experience that will keep users coming back?

Fortunately, we've seen this problem coming. There are a number of products on the market today, which aim to provide a solution; many of them involve integrating compression software into your image management workflow and tying that into your Content Management System (CMS) during publishing. While this process can work well, this does create a number of challenges that should be considered:

  1. Monitoring and Visibility - During the content creation workflow the image compression settings are often a black box. More often than not, content developers and webmasters have little visibility into these decisions, and do not have visibility into identifying where further tuning and optimizations can be done.
  2. Workflow Integration - Developing a tight integration to your enterprise class Content Management System can be challenging. This may lead to separate Image optimization processes that may not be standardized, losing visibility and control.
  3. Situational Performance - Your compression settings may not always be a one size fits all. The combination of varying source image quality and mobile network performance, can introduce serious performance and quality challenges. Can you imagine trying to download your pristine 2 MB image on a 3G cellular connection? I can, it would take approximately 20 seconds! Will your audience wait for that download? Mine don't!
  4. Quality Control - Similarly, the ability to control when, how, and what settings to use based on mobile vs. non-mobile network conditions can mean the difference between a conversion and abandonment.
So how can Akamai help?

Leveraging Akamai Ion and Property Manager, you can create match conditions at the Akamai Edge, enabling fine grain control to implement how and when your image compression settings are applied.

More importantly you now have the choice to vary your compression settings based on the network capabilities of the user. Targeting Mobile and Non-Mobile networks.

So what can this really do for me?

At the time of writing this (July 2015), according to HTTP Archive, for the Top 1000 sites on the Internet. JPEG based images comprised approximately ~500 KB of the total page size. Okay, that doesn't sound like much right?



Let's take a sample image

Screen Shot 2015-07-21 at 3.31.14 PM.png
Note: Compression is not linear and can vary based on the properties of the source image. Factors include color depth, metadata EXIF information, and existing compression or quality levels.

Looking at the data points above, there are two key takeaways to consider.

  1. There is no discernable difference between the images with regard to the visual quality
  2. 27% reduction in image size/weight using Akamai's Adaptive Image Compression
Lastly, for the sake of round numbers, let's assume we have 10 images on a web page. This would yield a page size of 420 KB vs. 330 KB respectively. Now, leveraging the same 3G cellular connection with Adaptive Image Compression, these pages would load a full half second faster! In our recent Performance Matter series, we collected data from nearly 3,500 respondents around the globe to identify the true impact behind these numbers. We found that 49% of the respondents expect a site to load in two second or less, and one in five users will simply not return if they consider your site to be slow. So, how much does that half second mean to you?

Raphael Edwards is a senior technical project manager at Akamai.