Best free image optimization and compression tools compared

In this post, I'll share some of the best image optimization tools for web developers to compress the images without compromising its quality.

Best free image optimization and compression tools compared

Adding beautiful images to your website or blog posts can make it much more attractive. The busy audience wants the information as fast as they can. They don't want to read the entire post and digest your content. So adding meaningful images will help your readers to quickly understand your content than reading a post that explains the same in a thousand words.

But the downside is, adding unoptimized images can make make your website considerably slower and hurt your search engine ranking and ruin the user experience.

What is image optimization?

Image optimization is a technique of reducing the size of images without losing its quality. Optimizing images on a web page helps to improve page load speed and save server resources.

Sample image optimization
Picture showing original image on the left and optimized image on the right.

In this post, I'll share some of the best image optimization tools for web developers to compress the images without compromising its quality.

1. ShortPixel

ShortPixel is the best image compression and optimization tool I have ever used. It offers three compression methods, Lossy, Glossy, and Lossless.

ShortPixel offers a free web based image compression tool where you can compress JPG, PNG, GIF and PDF files of up to 10 MB. For WordPress users, ShortPixel offers a plugin. With this plugin, WP users can compress up to 100 images a month for free. For small blogs and websites, it is enough and more.

You can try ShortPixel here.

Compress and optimize your JPEG, PNG and (animated) GIF files
Freely optimize your images with ShortPixel. Compress your images with up to 90% without any humanly visible differences.

I tested several other image optimization tools and found ShortPixel outperforming its competitors.


  • Supports PDF and GIF file formats.
  • It has a web interface.
  • Better compression.
  • Three modes to choose from.
  • WordPress plugin.
  • No file size limit in paid plans.


  • WordPress plugin may cause issues with some plugins.
  • Plans are based on the number of files to optimize.

2. Optimizilla

Optimizilla is another image optimization tool that can compress JPEG and PNG files. The best part of Optimizilla is it allows us to have control over the compression level and have a preview of compressed images.

Online Image Сompressor
Optimizilla is the ultimate image optimizer to compress your images in JPEG and PNG formats to the minimum possible size.

If you are looking for a free image optimization and compression tool, Optimizilla will be the best solution.


  • Completely free.
  • Adjustable compression level.
  • Option to preview before optimizing.
  • Offers Web interface.


  • No plugins or API.
  • Supports only JPG and PNG files.


Kraken is similar to ShortPixel. It has plans that start at $5 per month with a limit of optimizing 500 MB images per month. You can compress more images at a cost of $ per additional GB.

Like ShortPixel, Kraken also offers a WordPress plugin and Web interface. Kraken supports Lossy, Lossless and Custom compression options.

Kraken also offers Magento extension and cloud storage.

You can try Kraken's web interface here. Image Optimizer is a robust, ultra-fast image optimizer. Thanks to its vast array of optimization algorithms is a world ahead of other tools. Want to save bandwidth and improve your website’s load times? Look no further and welcome to!

The main difference between Kraken and ShortPixel is Kraken's plans are based on the Size of files whereas ShortPixel's plans are based on the number of files you optimize.


  • It Offers custom compression options.
  • Has a WordPress plugin.
  • Configurable optimization options in Expert mode.


  • High price tag.

4. Imagify

Imagify is the best choice if you are looking for bulk image optimization. It offers monthly and One Time plans. Monthly plans of Imagify start at $4.99 / month and the one time plan starts at $9.99. One-time plans are useful if you to bulk optimize a large number of images.

The web interface of Imagify can be accessed here.

Free & Easy Online Image Compression Tool by Imagify
Optimize your images online for free with the Imagify compression tool. It’s easy and only takes a few clicks!

Like other tools in our list, Imagify also offers a WordPress plugin.


  • Best solution for bulk image optimization.
  • Offers one-time plans.
  • Several plans to choose


  • Plans are based on the amount of data transfer.

5. is the cheapest solution. It offers a free plan with which you can optimize any number of images under 100 KB. does not have a monthly plan. Its yearly plan starts at $29. All plans of does not have any limit on the number of images or file size you can optimize.


  • Cheapest among all.
  • No limit on file size or the number of files.
  • It Offers an unlimited free plan.
  • Offers WordPress plugin.


  • No web interface.

A simple test

We tested these image optimization tools with three different images of different sizes and noted the following result.

**** Image 1 (64.4 KB) Image 2 (545 KB) Image 3 (845 KB)
ShortPixel 17.6 KB 141 KB 267 KB
Optimizilla (Adjustable compression) 9.2 - 25 KB 171 KB 230.4 KB
Kraken 21.62 KB 526.15 KB 834.11 KB
Imagify 49.3 KB 537.2 KB 842.0 KB
Winner ShortPixel ShortPixel Optimizilla

* Optimizilla has a configurable compression option. In this test, we configured the compression level of Optimizilla to 50%. Increasing the compression level will reduce image size than ShortPixel can.

The Verdict

From this result, It is clear that ShortPixel optimizes the images better than other tools. I'm not compelling you to choose ShortPixel. Optimizilla is a great free alternative to ShortPixel and beats ShortPixel in compressing images if configured for maximum compression. Now, it's your turn to test these tools and find the right tool for you.

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