WordPress Image Optimisation
WordPress Image Optimisation tools help you keep your website performing well by compressing large images and resizing them to fit. It not only drastically speeds up your site but saves on disk space while decreasing bandwidth costs.
Here are some of the top WordPress Image Optimisation tools:
- Imagify
- ShortPixel
- WP Smush
The WordPress Image Optimisation Tools Test
So I started with a plain WordPress install and added a basic theme and added 12 posts with full-size images downloaded from Unsplash. You can see the live unoptimised site here. It’s not too heavy to begin with, so it’ll be interesting to see how the tools improve the metrics.
Starting with Imagify
I cloned the unoptimised site to a folder and installed Imagify with a free account; it should be enough for the test leaving the default options set.
I scrolled down to and clicked Save and Go to Bulk Optimiser then hit the Imagif’em all button. It began and took about a minute and a half to complete. While it looked promising, I had a few errors crop up suggesting that I needed a paid plan to get the full benefit.
I used the little blue chat icon to talk to the team, and Sebastien happily added 1GB to my account to complete the testing, thank you! It took a further minute to complete the image optimisations.
With 47% saving in size, i’m confident it did a good job. I liked the WordPress media list view showing the image metrics. However, it felt a bit squished.
Testing out Shortpixel
Again leaving the settings as the default and pressing the Save and Go to Bulk Process button. This time the image optimisations took a while longer at around 15 minutes for the 106 images. To be fair, they were probably under a high load due to the success of the AppSumo deal they have just launched.
Shortpixel did an amazing job and saved me 74% in size. I liked the list view displaying showing not just the reduction and how many thumbnails it had optimised.
Trying out WP Smush
The final plugin that I tested was by WPMU called WP Smush. They have a pro version which I didn’t get to try as I no longer have a membership. As with before I installed the plugin and left it to the default settings; merely pressing the bulk smush button.
It was quick taking a minute to complete. I wasn’t impressed with the results though, saving just 5.7% in size with a Pro upgrade estimating that I would save up-to 12.7%.
The summary in the Media library looked nice, but with such minimal savings, I wasn’t impressed with the actual compression algorithm used.
The Results of the Image Optimisation Tests
The Baseline
Using the unoptimised site to set a baseline was the first challenge. The site came back with excellent scores.
Pingdom
Since the server is in Europe, I will be testing from Stockholm, Sweden. The performance grade came back as A with a score of 92.
With the results only showing minor performance measures it really was going to be a challenge for the image optimisation tools to make a difference.
GTMetrix
This tool gives a in-depth view, I configured it to use Chrome with a DSL connection (1.5Mbps/384 Kbps, 50ms) in the London, UK location. The performance scores came back as A (92%) Pagespeed and B (83%) Yslow.
WebPageTest.org
I set the test location to London, UK using Chrome.
Fully loaded Time of 2.441s for 31 Requests with Bytes In of 698 KB.
They also have a speed test for images powered by Cloudinary.
The baseline site scored a B grade with a potential compressed weight of 54%. What’s nice about this tool is that it dissects each image giving you the potential smart compression based on a recommended image format.
Note though your web-host would have to support these image types. Some newer formats such as JPEG-XR and WEBP are less commonly supported.
Google PageSpeed Insights
Most developers would know and PageSpeed Insights which is why I won’t go into much detail. The baseline scores were 74 / 100 for Mobile and 90 / 100 for Desktop.
Google Test My Site
This tool is Google’s latest test developed on top of WebPageTest technology which focuses on mobile and speed over a 3G network. The baseline site loaded in a fast 3 seconds.
All in all, this just shows that by default Unsplash are good at compression and WordPress is doing its job of cropping and resizing the images before displaying them in posts.
Dareboost
The baseline scores 72% with a Speed Index: 1139
The results for each test looked like:
Imagify scored impressive results!
While the page speed scores remained the same at 72% on Daraboost, it showed a breakneck Speed Index of just 649. Both Shortpixel and WP Smush scored with a modest Speed Index: 846 and 845. Google recommends you keep it below 1000 so all of the tools used would have achieved that.
According to WebPageTest.org the Imagify site had a Fully Loaded Time of 2.363s for the 32 Request with Bytes In of 617 KB. This speed is slightly slower than the Shortpixel website which had a Fully Loaded Time of 2.040s with Bytes In of 632 KB.
Because the site is hosted using a VPS, this could be down to network traffic or other variables, but both tools scored impressive results. On the Test My Site, the page loaded in 3 seconds using 3G confirming the speed. Imagify and Shortpixel scores were 79 / 100 for Mobile and 92 / 100 for Desktop. As expected the disappointing ratings of 77 / 100 for Mobile and 89 / 100 for Desktop were from the WP Smush plugin, it also seemed to cause Test My Site to take an extra second to load compared to the unoptimised site!
Pricing
Shortpixel is back on a lifetime deal at Appsumo get 5000 credits for life for just $29. We also secured anyone using our link an extra 50% credits!
Imagify has good rates, as for the approximate amount of images it depends on how big they were to start so this can be a bit deceiving.
As for the stock photos I tested the average was 2.67MB so ~384 images would fit in the Lite plan. However, because most images in WordPress are resized we end up with already smaller optimised versions needing further compression so this is where you will get more bang for your buck. Either way the performance was great so do try out Imagify for yourself.
