Today we will know the best image optimizer plugins for WordPress. Each one of them claims to be the best tool for this purpose. So we tested them in real life to see how they performed in reality. Our test results surprised the hell out of us. Read on to find out exactly what we discovered, especially about “popular” plugins.
Why bother with optimizing images?
Images make up about 21% of a given page size. The more images you use in your content, the longer a page will take to load. But you still need to use the image on your site. Optimizing your images in Photoshop or similar was once the only way to reduce an image’s size. However, it takes a lot of work and a certain amount of knowledge. Fortunately, there is a whole range of image optimization plugins for WordPress to do this for you.
Here are the plugins we tested.
Best WordPress image optimizer plugins
- Imagify
- Smush
- ShortPixel
- EWWW Optimizer
- Optimole
Imagify – image optimizer plugins
Imagify is a free plugin for WordPress, but you need to create an Imagify.io account to get the necessary APIs for the plugin to work properly.
Imagify Interface
You don’t have to fiddle around with multiple tabs, side menus or anything like that – the Imagify interface takes up a single page:
It’s a little scary at first glance, but there are really some settings you’ll have to worry about yourself, such as ‘optimization level’ and enabling WebP image support. A really neat feature is that you can optimize the images in your WordPress theme, or just add an entire folder of images instead:
The ‘Visual Compare’ tool is a nice touch – you can preview the different image compression levels available within the plugin:
Image Optimization
You can choose from three different types of image compression:
- Normal – minimal compression
- Aggressive – Medium compression (default setting)
- Ultra-maximum compression
As with most of these plugins, you can do a “bulk optimize” for existing images, but we wanted to test how it handles optimization for new images. It wasn’t very clear how to actually do this – it involved a bit of trial and error.
You need to upload the image first, and then go to your media library in WordPress to find the optimization settings:
Your image is optimized based on the Imageify plugin’s default setting, and in this case it was the ‘aggressive’ setting that trimmed the file size by 95.34%. In practical terms this means the file is shrunk from 555KB to 25KB in size.
You can choose to optimize to ‘Ultra’ or down to ‘Normal’ from this screen, as well as restore the image file to its original state. You can even compare the quality of the original file with the newly optimized version before publishing it:
Imagify Advantages
- Very impressive image compression
- Their free plan covers up to 25MB of image bandwidth per month
- Very easy to use minimalistic interface
Imagify Disadvantages
A separate tab for ‘admin’ settings would be nice, but we’re just nitpicking here.
Smush – image optimizer plugins
Smush (The WP Smush) is one of the best image compression plugins.
In fact, if you ask most website owners what they use for image compression they will probably say, “Smush”.
This explains why the plugin has over 1,000,000 active installations.
But let’s see if it lives up to its reputation.
Smash interface
The dashboard is very clear and tells you how many photos you have smooshed and how many photos currently need to be smooshed:
The rest of the Smush functions are accessible from a menu on the left side of the screen:
- Bulk Smash – Compress all your photos at once
- Directory Smush – Compress all images in a given directory
- Integrations – Gutenberg, WP Bakery Page Builder, Amazon S3 NextGen Gallery.
- Lazy Load – Suspends loading of images below the fold
- CDN – Enable WPMU Dev CDN for Smush
- Tools – Detect and display malformed images
- Settings – Accessibility, Translation, Usage Tracking, App Data and API Status
Honestly, the only settings you need to look at are ‘bulk smash’ and ‘lazy load’.
Image optimization
Smoosh automatically compresses new images by default, so we had to turn off that setting to see what Smoosh was doing.
- The Smush dashboard gives a clear visual representation of your statistics and tasks
- This is a 100% free plugin
ShortPixel – image optimizer plugins
ShortPixel 2 is a name you might not be instantly familiar with, but it’s developing a reputation as one of the best image generators on the market. The first thing we need to cover here is that there are two different ShortPixel plugins:
- ShortPixel Image Optimizer (SIO)
- ShortPixel Adaptive Image (SAI)
ShortPixel Interface
They went for a minimalist approach to their interface which is a breath of fresh air compared to other plugins:
Under the ‘General’ tab you can select from three compression levels:
- Lossy – High compression, low image quality
- Gloss – Nearly identical to the original image
- Lossless – lower compression, higher image quality
WebP support is enabled by default, as images are lazy loaded, so you must choose which type of compression to use.
The ‘Advanced’ tab contains the URL to the API and 99% of you will never need it.
So again, almost no configuration is involved.
Image Compression
ShortPixel takes care of your image compression needs “on the fly”, so the results are a bit harder to measure.
In fact, the only way to find image compression statistics is through their website.
And you need to download a separate report that updates once every hour:
ShortPixel Advantages
- Set image optimization and forget it
- Excellent reduction in image file size
- No fiddling with complicated settings
- Free account available (100 images per month)
ShortPixel Disadvantages
- They require a reporting dashboard within the plugin
- Several available plugins are confusing
EWWW Optimizer – image optimizer plugins
With over 700,000 active installations and a 4.5-star rating, EWWW seems like a good choice as your image compression plugin. After all, if hundreds of thousands of site owners are happy with this, they must be doing something right.
Interface
EWWW Image Optimizer has a very visual dashboard, showing what level of image compression you can expect and how much file space you’ve saved so far. You may have noticed that its compression level is set to 20%, which still doesn’t sound too bad.
You may have noticed that its compression level is set to 20%, which still doesn’t sound too bad.
You may have noticed that its compression level is set to 20%, which still doesn’t sound too bad.
To access their ‘Pixel Perfect Plus’ or better compression tool you need to purchase an API key. We will discuss this failure in a little more detail in the next section.
The rest of the interface is accessed through a tabbed menu, but we think new users can feel a real sense of overwhelm when they see dozens of different options that can be enabled or disabled.
Image compression
Like Smush, EWWW Image Optimizer automatically compresses new images uploaded to your WP media library. Unfortunately, the only way to do this is to manually edit your wp_config.php file, or what they refer to as “override options”.
This oversight makes the plugin instantly accessible to many people.
We ran our tests using the plugin’s default optimization setting and got these results: That 9% reduction in file size (58.8KB) dropped our test image size from 555KB to 496.2 KB.
It performs slightly better than Smush but lags far behind all the other plugins in this roundup. The only way to improve this result is to purchase an API that charges $0.0003 per image. Or you can pay $9 per month for their ExactDN Image CDN instead.
This may seem like a smart marketing move, but it effectively makes their free plugin useless. It is a lead gen tool equipped as an image optimization plugin.
EWWW Optimizer Advantages
- EWWW Image Optimizer is free
EWWW Optimizer Disadvantages
- The interface is a hot mess
- Image compression is very poor
- The free version of the plugin is severely limited in functionality
Optimole
Optimole is a product that has a lot in common with both Imagify and ShortPixel in that it offers cloud-based image optimization and compression. Or, in their own words, “. Real-time image processing and an image CDN for WP.”
And as with other cloud-based image optimization tools, you’ll need to register for a free account to use this plugin.
Your Optimole account is not “free forever” – it has a 1GB photo limit
Interface
We liked the Optimole interface – they managed to keep it deceptively simple, but with all the settings you need within reach.
You have two options between the ‘Dashboard’ and ‘Settings’:
Under Settings you have two main options:
- Enable image replacement
- Scale images and lazy load
And under the ‘Advanced’ menu you can choose from the:
- Compression Level – Low, Medium, or High
- Image Resizing – Resize large images to fit
- lazy load (enable a simple placeholder)
- Exclusions – Files that you don’t want to optimize
- Watermark – Add a watermark to your image to prevent piracy/theft
Accessing plugins means going to Plugins -> Installed Plugins and then scrolling down to click ‘Settings’ for the plugin. We hope they fix this with some sort of admin bar or contextual menu system in a future update.
Image Compression
So the interface looks great, but how good is it at reducing image file sizes? Well, here’s where things get a little different. It doesn’t integrate with the media library, so we didn’t see a reduction of image files there. After some messing around and refreshing we went back to the dashboard and there we got the result: Our test image is now 21.8 times smaller than before, which sounds great.
Optimole Advantages
- Impressive image reduction capabilities
- The watermark feature is pretty cool
- Streamlined and intuitive interface
- 5GB free image bandwidth per month
Optimole Disadvantages
- Actually accessing the plugin is a task
- The reporting is messy, to say the least
Conclusion
And that brings us to the end of our WordPress image optimizer comparison, where Imagify emerges as a clear winner. We were genuinely surprised by how well both Imagify and Optimol performed in our tests.
However, this is based on our complete ignorance of the plugin and is not a negative opinion on our part. ShortPixel is our tool of choice, as it’s pretty much automated – we let it do its thing.
As you probably know, we often like to methodize everything we do.
But with that said, we can run more tests with Imagify on live sites to see how it copes.
