Comparing The Best WordPress Image Optimization Plugins

In this test, I set out to compare the performance of the most-recommended image compression plugins for WordPress to see which one is the best of the best.

Testing Parameters

I used only the free versions of each plugin and I tried to test them as a regular user. What I mean by “regular user” is someone who doesn’t do any pre-processing in software like Photoshop, which is what I usually do.

The first test was performed with a 10.4MB stock image. That’s a pretty small size for a stock image and I wanted to see what the plugins could do.

As you see in the results, some of the plugins won’t compress files that large with the free versions.

So a second test was in order.

The second image is also a stock image that I pre-processed in Photoshop by reducing the ppi (pixels per inch) from 300 (print quality) to 72 (web quality).

Here Are The Results – Test #1

I was not able to test TinyPNG because at the of this test their site was giving me an “internal server error” whenever I tried to get an API key.

In this test, Imagify and WPSmush free versions refused to compress the image because it was larger than 1MB. EWWW only allows lossless compression for the free version.

Bottom line, the free versions of ShortPixel and Optimole are pretty much tied in compressing large, stock images. The type of image a client or a beginner would add to a website.

Here Are The Results – Test #2

TinyPNG wasn’t working at the time of this test either.

Imagify refused to compress the image because it “was already compressed”, even though the other plugins had no trouble compressing it further.

EWWW and WPSmush only allow Lossless compression in the free version, so they did not compress the image by much.

In top spot was Optimole, with a very impressive compression rate. ShortPixel was not far behind. These two plugins were also the top 2 in the first.

Conclusion

ShortPixel and Optimole were the top two plugins in both tests. They did not complain about the first image being too large and they didn’t complain about the second image’s PPI being reduced to 72PPI.

They also did not hold back on the compression because we used the free version. The biggest difference between these two plugins is in the free version ShortPixel allows you to compress 100 images per month with unlimited bandwidth (image views). The free version of Optimole allows you to compress 1GB of images per month with 5GB of bandwidth (image views).

That means if you have a high traffic website, Optimole could stop serving compressed images until your bandwidth resets at the beginning of the month. That is not an issue with ShortPixel.

Another benefit of Optimole is that it has lazy loading built right into the free version of the plugin version and it detects the visitor’s devices size and servers the perfect size of image to them.

Both Optimole and ShortPixel are great image compression choices. I recommend that you try their free versions on your site and see which one suits your needs the best.