The Speed Study Goal

My goal with conducting these Speed Studies is to find out which strategies are the best at improving our site speed.

I’ll implement each strategy using the following approach:

  1. Setup the strategy on all 8 of our live test sites
  2. Then for the following 3 weeks, gather the load times from our Desktop Speed Test using GTmetrix. Each week we will test from a different location, starting in Dallas, then London and finishing off in Sydney.
  3. Next measure the impact of each strategy by comparing the average speed before and after
  4. Ultimately decide whether the strategy works?

ShortPixel Speed Study

With our 2017 baseline setup and Imagify, EWWW and Kraken already put to the test, lets try the final image optimizer to be analyzed this year. What we’re expecting to see is the page size will reduce, what will be really interesting is whether there is any real speed improvement. The plugin we will use for this Speed Study is ShortPixel Image Optimizer, which is a freemium offering with over 30,000+ active installs.

To kick off this ShortPixel Speed Study, the first step is to remove Kraken and then install the ShortPixel plugin. I followed these installation & setup steps for each of our test sites.

All Setup

I have now followed this process on all 8 of our Live Test Sites.

Next up is 3 weeks of testing – I am curious to see how much our speed differs between Imagify, EWWW, Kraken & ShortPixel?


The Results – 23rd April 2017

After 3 weeks of testing, lets take a look at how much of an impact installing ShortPixel has had on our 8 hosts.

Speed Study 12 - ShortPixel Results Table


So how did ShortPixel perform? The average load time across 3 different testing locations was 3.51s, which is 2% faster than Kraken.

When we dig into the 3 locations we test from, Dallas & Sydney were quicker with ShortPixel, while Kraken was fastest in London. And there was no difference in the other factors such as Page Size, Google & Yahoo Scores.

So when it comes to making a call on whether ShortPixel is helpful, the answer seems as though it is a YES. To fully confirm, let’s take a quick look into how each of our hosts performed individually…

Individual Host Performance

Let’s now take a look at how our individual hosts performed:

Speed Study 12 - ShortPixel - Individual Host Performance

Major Observations

  • The results are mostly positive when it comes to our individual hosts:
    1. GoDaddy, SiteGround, HostGator, Bluehost & DreamHost all experienced minor improvements of between 1% & 6%.
    2. InMotion Hosting, Web Hosting Hub & Namecheap had minor negative impacts, ranging from 1% to 5%.
    3. But the big news story again, is that DreamHost continues to have very poor speed!! These results confirm that DreamHost is unable to compete and will be replaced for all future tests by Lightning Base. For the purposes of our Image Optimizer comparison, I’ve excluded DreamHost in the table below.
  • The overall observation from where I sit is that the difference between Kraken & ShortPixel is fairly minor, with just 0.03s separating them. As for a recommendation, ShortPixel is preferred.
  • With all testing now complete, check out the results for all 5 Image Optimization plugins side by side.
Speed Study 12 - ShortPixel Results Table excluding DreamHost

What’s Next?

We have now finished speed studies into 4 Image Optimizer’s, with the overall results included in our post on Fastest Image Optimizers. As far as Speed Studies go, it’s time to change gear and take a look into Caching plugins.

So Speed Study #13 will focus on what speed improvement is possible with WP Super Cache?

Speed Study #13: WP Super Cache