You are probably reading this because you are trying to increase the load time and performance of your site with a WordPress image optimizer plugin.  When you are trying to optimize your site for speed, it is critical that you pay attention to images.  In general, while image compression is only one little item on your checklist of site optimization factors, it may be the one that makes the single biggest impact on speed.

When you are trying to optimize your site for speed, it is critical that you pay attention to images.  In general, while image compression is only one little item on your checklist of site optimization factors, it may be the one that makes the single biggest impact on speed. Why?

Well, when you think about it, you can do javascript compression all day long, but all 50 javascript files that you are loading to make your sites do fancy things are still very likely to be under 1 MB in size.  But, in one fell swoop, you can upload a 5 MB image to your site and singlehandedly increase your load time by minutes.

Offsite Image Preparation

Before we get too in depth on the power of image compression plugins, you should be doing some basic image preparation before uploading to your server.  Ideally, before an image goes up, you will:

  • Name it in an SEO friendly and readable way.  So no e8932erje8f9h.png – instead john-doe-bio.png.  Something that you can read that will make sense to you later, and something that will accurately describe to search engines what the image is, and ideally include your keyword if you can.  My image at the top of this page is called wordpress-image-opimizers.png
  • Resize it to reasonable dimensions.  NEVER upload full-size images from a digital camera. The biggest you want an image to be is probably 1920 wide and 900 tall.  Tha would be for a full-screen high-resolution image.  If the image will not be used that big – but will be used in a column that is never wider than 300px, size the picture to 300px wide.  The closer it is to the actual pixel size it will be using, the better.

What does a WordPress Image Optimizer Plugin Really Do?

If you’ve resized your image, what is the image optimization plugin on your site going to achieve?  Well, size isn’t just dimensions.  Many images can be compressed down to take less space by using intelligent compression techniques.  Some of these techniques are lossless, meaning your image looks exactly the same.  Some are ‘lossy’ meaning you may lose some image quality.  When you use a good plugin, even the lossy compression is barely noticeable, but the savings you may experience in size and speed are significant.

A good optimization plugin will do two things.  One, it will do a one-time search of your existing media and compress it all for you.  Two, every time you upload a new image, it will apply the correct compression settings.  If you’ve resized your images well and given them good names, this really is the power trio that is going to give you high quality, high-performance images for your site.

The Hidden Cost of Image Compression

Now, there is something that most people don’t think about.  You are trying to compress your image to save site speed.  If you upload a lot of images, there are image compression plugins that take a huge amount of server resources to run and check in with external servers and will slow your site down at a server level, not a page load level.

WP Smush, a freemium plugin by WPMU Dev is one of those.  We actually have stopped using this on our platform and have proactively started removing it from client sites to increase their performance, and it is measurable and significant.

So what are the alternatives?

Our Top 4 WordPress Image Optimizer Plugins

We are currently using http://imagify.io for our own sites.  It is not free, but it works well in tandem with wp-rocket (also not free) and has great performance.

For clients on our managed WordPress hosting platform who want great plugins that don’t impact the servers, here are some alternatives that work well that we recommend regularly:
https://wordpress.org/plugins/tiny-compress-images/
https://wordpress.org/plugins/kraken-image-optimizer/
https://wordpress.org/plugins/ewww-image-optimizer-cloud/

We always love the advice of the guys over at Flywheel as well, what they have to say about image compression can be seen at this link: https://getflywheel.com/wordpress-support/flywheel-guide-page-speed-tests/#optimize-images

Questions?  Feel free to post in the comments below and we’ll get back to you with answers!