Lossy image optimization plugins

ShortPixel – best free WordPress image optimization plugin

I tested three WordPress image optimization plugins and picked the best – ShortPixel Image Optimizer. Compress JPEG & PNG images plugin came in second, while WP Smush is on the last place. Strange considering WP Smush is the most popular WP image compression plugin out there. Wonder why it’s last on my list? Keep reading.

What does it mean to optimize images for the web?

First, let’s define what optimizing images means. Here’s the quote from GTmetrix:

Optimizing images for the web means saving or compiling images in a web friendly format depending on what the image contains. Images hold data other than just the pixels we see on the screen. This data can add unnecessary size to the image which leads to longer load times as the user waits for the image to download. -> GTmetrix

In other words optimizing image means compressing and removing all the unnecessary data that comes within the image. This way file size of the image is reduced by as much as 80%. Then we can draw a conclusion that image optimization is using the smallest file size which is still visually acceptable.

What are the reasons to optimize images?

If images play a significant role on your site, optimizing them could be essential for the success of your business. Reasons for image optimization include:

  • Decreasing page loading time – page load time is a major factor in a site’s success. It is an important part of website’s user experience. A user that has to wait is likely to hit the back button on the website. Losing customers that way should be unacceptable.
  • Decreasing bandwidth used – not optimizing images wastes precious bandwidth that will end up costing you money, customers, or both.
  • Saving hardware storage.

Difference between lossy and lossless image compression

There are two ways to optimize images – lossy and lossless compression. Images stored in a lossy format will look slightly different (worse) than the original (uncompressed) image. But this is barely visible, and impact on the page speed justifies it. That is why lossy compression is good for the web.

Images saved in lossless format retain more information than images saved in the lossy format. For this reason, lossless compressed images have a lot more data and much larger file size. That hardly has any impact on page load time in comparison to lossy image compression.

Why WP Smush is not the best free image optimization plugin

WP smush plugin

So if you are already familiar with the benefits of optimizing images for the web, chances are you are using WP Smush. WP Smush is the most popular image optimization WordPress plugin with 800000+ active installs. With this plugin, you are not limited to the number of images per month you can optimize for free.

However, there is one huge downside of WP Smush free version: it doesn’t optimize the original image. But what does it do, I hear you ask. Well, it optimizes all other image sizes that are created automatically by WordPress (and often your theme as well).

WP Smush PRO gives you the option to optimize the full-size image, but it comes with a price tag of 49$ per month.

For me, this is a problem because I upload images in the exact size I need for my articles. At first, I started using WP Smush without even considering other alternatives because I thought the most popular image compression plugin in WordPress plugin directory should be the best. When I found out through GTmetrix report that my images are not optimized for the web, I raised my eyebrow.

That discovery motivated me to write this article and share what I found out because these two alternative plugins I suggest are not nearly as popular as WP Smush.

Fortunately, using them, it is possible to get full-size image compressed as well.

Best free WP Smush alternatives


Shortpixel plugin

First free images optimization WordPress plugin that I recommend is ShortPixel Image Optimizer.

That is a plugin I use, and it allows me to:

  • choose between lossy and lossless image compression
  • save and keep a backup of original images in a separate folder, just in case.
  • automatically resize large images if necessary.
  • compress PDF files.
  • remove the EXIF tag of the image.
  • create WebP versions of the images for free.

Compressing PDF files and creating WebP versions of the images are the two features that I didn’t see elsewhere and that is also something that makes ShortPixel a standout option.

Two more features that I didn’t try yet are:

  • automatically optimizing images added by users in the front end, which sounds great.
  • glossy compression that creates images almost pixel-perfect identical to the originals which sounds like a great option for photographers.

You are not limited by any of their features in a free plan! You get all the options in a free plan which is great. And they do have a great array of options. The only limitation is the possibility to optimize 100 images per month. If you need more, you can choose a SHORT plan which allows you to optimize 5000 images per month for a monthly fee of only $4.99. That is TEN TIMES less than you would have to pay for the WP Smush PRO. They also have an alternative pricing model: one-time plans that allow you to optimize 10, 30 or 50K images or photos.

The only limitation is the possibility to optimize 100 images per month. That is more than enough for me, but if you need more, you can choose a SHORT plan which allows you to optimize 5000 images per month for a monthly fee of only $4.99. That is TEN TIMES less than you would have to pay for the WP Smush PRO. They also have an alternative pricing model: one-time plans that allow you to optimize 10, 30 or 50K images or photos.

Compress JPEG & PNG images plugin

TinyPNG plugin

The second option for WordPress image optimization is Compress JPEG & PNG images plugin. This plugin doesn’t have as many options as ShortPixel Image Optimizer, but it does include 500 images in the free plan.

If you need more, you will pay only $0.009 for each image above 500 free optimized images. That is also great as you only pay for the number of images you compress. This plugin allows you to choose which image sizes you want to compress on upload. Because WordPress has four alternative images sizes by default and your theme might create some more as well, this could be a very useful option.

 WP Smush vs. ShortPixel vs. TinyPNG

OK, so we determined that Shortpixel offers the most features, but how does it perform? Let’s make a test. I used the jpg image below and optimized it with all three image optimizer plugins from this articles.

Coffe image optimized by ShortPixel

The image you see is optimized by ShorPixel plugin. This compressed version has the size of 94 KB while the original had 291 KB. Check out the table below to see how that compression compares to the WP Smush (see compressed image) and TinyPNG (see compressed image).

Features WP Smush ShortPixel TinyPng
Original image (291 KB) compressed to: 267 KB 88 KB 94 KB
Compress original full-size images NO YES YES
Back up original image NO YES NO
Choose between lossy or lossless compression NO YES NO
Optimize PDF NO YES NO
Choose which image to optimize on upload YES (apart from original size) NO YES
Create WebP version of an image NO YES NO

As you can see from the table above, ShorPixel is by far best option of the three. Not only it compressed the image best, but it has also almost all of the features other two have and much more than that. WP Smush is actually the worst option to choose. If I had ten 291 KB images in this article, WP Smush would compress them to 267 KB (it only removes EXIF data). That means my desktop users would have to download 1790 KB of data more (!) than if I used ShorPixel for the same task. Talk about the bandwidth save and page load time boost just by choosing ShortPixel to compress images. And it is done automatically; you don’t have to do anything.  


So if you see Optimize images warning in GTmetrix report, install ShortPixel or TinyPNG WordPress image optimization plugin. Your users will be grateful, and Google will love you more 😉



I am ShortPixel Image Optimizer affiliate which means if you buy subscription through the link in this post, I will earn some cash as their partner. However, I believe in this product and I am personally using it as well. This is why I am recommending it in the first place. If you choose to purchase one of their plans, you will pay the same price – no extra cost for you.

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