By now, you probably know the importance of website loading times and page speed. The internet has been abuzz with news about how loading times impact your bottom line and Google has been pretty clear about favoring fast loading websites and blogs.
While there are many ways to optimize the speed of your website, one of the first places you should look to make improvements are the images you use.
Images play a crucial role on every website. They help you showcase your brand, add a touch of personality, and help you tell the story behind your business or every blog post you write.
Unfortunately, images also tend to be one of the biggest culprits when it comes to page load times. To help you get started with optimizing your images, in this post we’ll take a look at 6 best image optimization tools and compare their results.
6 Best Image Optimization Tools For WordPress
For the purposes of our test, we’ll use a JPG and a PNG image shown below:
Photo by Luis Poletti on Unsplash
Photo By Bruce The Deus at Italian Wikipedia
The same JPG and PNG images above were used across all tests with all the plugins mentioned below.
1. EWWW Image Optimizer
When you install and activate EWWW Image Optimizer, it will automatically optimize any images that you upload to your website. It can optimize JPGs, PNGs, GIFs, and PDFs and it also allows you to go through your existing media library and optimize already uploaded images. The plugin can also convert images to the best format if you decide to enable this option in the plugin settings.
One of the benefits of EWWW Image Optimizer is that it allows you to optimize images using their specialized servers to provide both lossy and lossless compression. In short, this means that image optimization won’t cause additional load on your server. The core plugin is available for free. Paid plans are available as a monthly subscription or prepaid plan starting at $.005/image $9/month for 3000 images respectively.
How did the plugin do?
| Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| JPG | 3.4MB | 3MB | 13.8% | Lossless |
| PNG | 4.4MB | 80KB | 98.3% | Lossless |
2. Smush Image Compression and Optimization
Developed by WPMU Dev, Smush Image Compression and Optimization plugin is available in both free and premium versions. After you install the plugin, you’ll be taken to the plugin settings page where you can see how many images were already optimized and configure which thumbnail sizes you want the plugin to optimize, whether images should be resized, and more. The free version of the plugin is limited to resizing images that do not exceed 1MB in size.
The plugin can optimize your JPEG, GIF and PNG images individually or you can use their bulk optimize feature. In addition, you can optimize image files that are uploaded outside your media library such as images stored in your theme files.
Pro features of the plugin are included as part of WPMU Dev membership at $49/month and allow you to compress images up to 32MB in size and convert PNGs to JPGs as well as make a copy of the original image.
How did the plugin do?
| Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| JPG | 813KB | 793.6KB | 5.5% | Lossless |
| PNG | 631KB | 616.3KB | 0.1% | Lossless |
3. Optimus
Optimus WordPress Image Optimizer plugin was developed by KeyCDN, a company that provides CDN services at competitive prices. The plugin itself is available in three different versions, each allowing you to compress JPGs and PNGs.
The free version of the plugin puts a serious cap on the file size limits. If your image is larger than 100KB, the plugin will not process your image.
Their paid plans start at $19/year and allow you to process images that are up to 5MB in size and allow you to use it for images used on your own and client projects. Both paid plans allow you to convert images to WebP format and use their Developer API.
How did the plugin do
| Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| JPG | 97KB | 53KB | 45.3% | Lossy |
| PNG | 76KB | 73KB | 3.9% | Lossy |
4. ShortPixel
ShortPixel is a freemium plugin that can compress JPGs, PNGs, and GIFs. After the plugin installation, you will prompted to sign up for an API key by providing your email address. Every uploaded image will be automatically optimized and you can also bulk optimize images already present in your media library.
The plugin supports both lossy and lossless compression methods. It will also optimize all the thumbnails created by WordPress, remove EXIF data, set a maximum resolution for your images, and save a backup of every image you upload to a new folder.
The free version of the plugin allows you to optimize 100 images per month. You can purchase extra credits separately starting at $4.99/month or earn them by referring new users to the service. Once the optimization process is complete, the plugin will provide you with a downloadable report of the optimization process.
How did the plugin do
| Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| JPG | 1.4MB | 447.88KB | 69.39% | Lossy |
| PNG | 4.4MB | 1.92MB | 57.07% | Lossy |
5. Imagify
Imagify plugin is relatively a new plugin in image optimization scene. Developed by the team behind WP Rocket, a WordPress caching plugin, this tool allows you to optimize all the popular image formats. It requires an API key to be used and it offers 3 levels of compression:
- Normal – uses on lossless compression
- Aggressive – Uses lossy compression with minimal data loss
- Ultra – uses lossy compression but allows for minor loss of quality
Once you’ve entered the API key, you’ll be prompted to go to the settings page where you can choose the level of compression, enable the ability to keep the original images in a separate folder, resize your images to set width, and remove all EXIF data.
The free plan allows you to process 25MB of images every month and you will receive a 25MB bonus upon registration. Premium plans can be purchased on a monthly basis, starting at $4.99/month for 1GB optimizations and unlimited file size. Imagify also offers one-time plans that start at $5.99 for 500MB of images.
How did the plugin do
| Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| JPG | 1.4MB | 876.45KB | 40.1% | Lossless |
| PNG | 1.2MB | 639.39KB | 55.31% | Lossless |
6. Kraken
Kraken.io Image Optimization plugin allows you to optimize and resize new and existing WordPress image uploads using their Kraken.io Image Optimizer’s API. The plugin supports both lossless and intelligent lossy optimization and it can optimize JPGs, PNGs and GIFs, including animated GIFs. Bulk optimization feature is supported as well as the ability to preserve all EXIF data.
Aside from allowing you to optimize animated GIFs, Kraken is one of the few plugins that work even on local installations of WordPress.
The free version of the plugin allows you to optimize image files up to 32 MB in size and up to 100MB of images. Premium plans start at $5/month with a limit of resizing 500MB of images.
How did the plugin do
| Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| JPG | 1.4MB | 1.MB | 7.96% | Intelligent Lossy |
| PNG | 1.5MB | 510KB | 64.35% | Intelligent Lossy |
Wrapping Up
Optimizing your images is a good way to start improving your website load times. While the tests above are a nice starting point to give you an idea of plugin’s performance, keep in mind that the compression results depend on the type of image you use. Here’s the final table comparing all the plugins side by side:
| Plugin | Image File Type | Original Size | Reduced Size | Percentage Reduced | Compression Used |
| EWWW Image Optimizer | JPG | 1.4MB | 1.3MB | 7.2% | Lossless |
| PNG | 4.4MB | 80KB | 98.3% | Lossless | |
| Smush Image Compression | JPG | 813KB | 793.6KB | 5.5% | Lossless |
| PNG | 631KB | 616.3KB | 0.1% | Lossless | |
| Optimus | JPG | 97KB | 53KB | 45.3% | Lossy |
| PNG | 76KB | 73KB | 3.9% | Lossy | |
| ShortPixel | JPG | 1.4MB | 447.88KB | 69.39% | Lossy |
| PNG | 4.4MB | 1.92MB | 57.07% | Lossy | |
| Imagify | JPG | 1.4MB | 876.45KB | 40.1% | Lossless |
| PNG | 1.2MB | 639.39KB | 55.31% | Lossless | |
| Kraken | JPG | 1.4MB | 1.MB | 7.96% | Intelligent Lossy |
| PNG | 1.5MB | 510KB | 64.35% | Intelligent Lossy |
Use the comparison above as a starting point to choose a plugin and test it on your own site.
Why didn’t you use the same images for the comparison? A comparison test doesn’t mean very much if objects being tested are all different.
Which compression did you pick for your tests? And what do the compressed images look like? Just knowing the % isn’t very helpful without any context.
Keep away from Imagify. They will bill you automatically without any prior notice renewal which is illegal in many countries. Stole 35$ from me in the same way! I also deleted wp rocket, Obviously I don’t want to help a business which uses dirty tactics.
Hello Amir, thank you very much for informing as about the process of Imagify.