While testing your website’s load speed using tools like Pingdom, you might have noticed that images add a lot of weight to your pages, thereby slowing it. You can not avoid images unless you have a text-oriented blog. So what is the best way to solve it? The answer is, make each image as lightweight as possible. Since you are using WordPress, there are a couple of plugins that help to compress and reduce the size of images you upload to your site or blog. In this post, I going to compare top image optimization plugins available in the plugins directory.
As I also run a couple of photo-heavy blogs, I am especially interested in image SEO also. Photos generally use JPEG format while screenshots and illustrations work best in PNG format. So while comparing each plugin, we will check how efficiently they compress images in both JPEG and PNG.
And finally, we will also find how you can compress images using photo editing software like Photoshop.
We will be looking at:
- How plugins optimize JPEG & PNG
- Manual optimization using image editing software – pros and cons
- Do you really need an image optimization plugin?
This is the list of plugins I am going to compare here:
- WP Smush
I have included only the plugins that are actively maintained and have at least 10k installs.
For testing, I chose a JPEG photo that I clicked myself and a PNG illustration from pixabay.com.
Full size (1280x853px): 724.76KB
Large: (1024x683px): 244.99KB
Medium (300x200px): 24.66KB
Full size (1280x648px): 483.71KB
Large: (1024x518px): 334.47KB
Medium (300x152px): 54.28KB
Omitted the smallest thumbnail as it is too small.
Results after Compression
With a generous free plan, ShortPixel is one of the best image compression plugins out there. As you can see from the above tables, ShortPixel surpassed all other plugins when it comes to JPEG compression.
In addition to the default lossy compression, ShortPixel offers a Glossy algorithm which aims at photographers who need critical image quality while compressing.
reSmush is the only plugin in this list that is completely free to use. What it does completely free of charge deserves applause. It is on par with other plugins when it comes to optimizing both JPEG and PNG formats.
The plugin allows you to manually enter a quality level from 0 to 100. The default value is 92, which a little high in my opinion. For better compression, enter a safe value in the range of 75 to 85 which improves reductions a lot for JPEG images.
The plugin saves a renamed version of the original file in the uploads folder. This comes useful when you want to re-optimize images after changing a quality setting. However, I couldn’t figure out how to disable it so as to save disk space.
In short, reSmush.it is the best free image compression plugin I have found so far. You should definitely check it if you haven’t already.
Imagify excels both in JPEG and PNG compressions. It offers three settings for quality – normal, aggressive and ultra. Aggressive is the default setting which helps to achieve good reductions without any noticeable image degradation.
The monthly limit is 25MB and the maximum file size you can upload is 2MB.
TinyPNG Compress JPEG & PNG Images
With over 100k active installations, TinyPNG is another popular compression plugin. The free plan of TinyPNG allows you to upload 500 images per month. Unless you upload too many photos each with several thumbnails, this limit will be hard to reach for most users.
However, the paid plan starts at $25 per year while most of the other plugins offer monthly plans.
Kraken.IO has a powerful image optimization API which helps to compress your WordPress images with their plugin. In addition to that, you can also try their Web Interface to get a feel of the whole job it does.
The free account allows you to process 100MB of images. You have to pay thereafter. The plans start at $5 per month which raise the limit to 500 images per month.
EWWW Image Optimizer
The free version of EWWW Image optimizer offers only lossless compression for JPEG images. So the savings are comparatively small.
The lossy compression settings like Premium, Premium Plus, and Pixel Perfect Plus are available only in the paid version. One lossy setting (Premium) is available for PNG though.
Smush is the most popular image compression and optimization plugin with over 1 million active installs. However, the free version gives only lossless compression techniques. The results are almost negligible according to my tests.
The ability to compress the original file is also locked in the pro version. This further reduces the usefulness of the free plugin.
Smush is a product of WPMU Dev who makes several other tools also to supercharge your WordPress site. They have a membership plan which costs you around $49 per month. So, if you are looking to be a part of WPMU, Smush is worth considering.
Do you actually need a Plugin to Optimize Images?
Not necessarily. If you use software like Photoshop or Gimp, you can manually set a quality level for each image before saving. For PNG, be sure to use PNG-8 over PNG-24 whenever possible.
Advantages of Manually Optimizing
- Ability to preview results before saving
- It can give greater savings if used correctly
- Gives more control on the image quality
- You can avoid an extra plugin
On the contrary, using a plugin has the following advantages:
- Saves time
- The quality of a compressed image is sometimes better. I have found that ShortPixel produces better quality JPEGs than Photoshop for the same size.
- To eliminate page speed warnings about image size, plugins can be better as it can automatically calculate the lossless compression opportunities for each of your images.
You should definitely optimize all of your images for better performance and user experience. There is no question in that. However, you can do it either manually or by using plugins.
So these are the final picks:
So far, we have seen that ShortPixel is the best in terms of compression savings. Imagify is also equally capable. If you are looking for a completely free plugin, then there is nothing comparable to
Apart from all these, Optimole is another plugin that is quite popular. It takes a slightly different approach by offering a CDN too.