How to Reduce Image File Size On Your Website by Over 60%

The logo at CustomizedWalls.com was reduced in size by 69% after being optimized at CompressPNG.com

This image is an example of how a simple logo on a website, in this case CustomizedWalls.com could be reduced in file size by a full 69% just by using CompressPNG.com

Back in 2010 Google officially stated page speed was added as a ranking factor for its search results. This means the speed at which your site loads can have an impact on the resulting position of your web page in search engine results. As a result, web marketing and development companies  such as ShelterSEO.com have paid more attention to the download speed of web pages for the benefit of our clientele. One of the most significant culprits for slow page speed has been the image sizes within the page and how poorly they have been optimized for the various devices likely to view them. As a result, I chose to test some of the available free online tools to reduce image file size for interior designers so their often image-heavy sites can download faster; a great result for everyone.

“…our users place a lot of value in speed — that’s why we’ve decided to take site speed into account in our search rankings.” – Google

I tested two file types that are incredibly common on websites; JPG and PNG. The online tools I used were CompressJPG.com, CompressPNG.com and Kraken.io. All of those tools offer free online image optimization tools you can easily use to compress an image before you place them within your site and the size savings are immense!

The question I answer here is… which tool provided the best overall results?

PNG Compression Tools Reviewed

Using CompressPNG.com and Kraken.io I optimized several images to see how they would compare in terms of file size before and after optimization. I also considered the visual quality afterwards but soon found there were not noticeable differences across any of these programs; even when using lossy compression (where images lose some quality in favour of file size) was utilized. All-in-all, the images still looked great which is the way it should be. Since I don’t want to draw this article out into an overly technical review, here are the results:

An image of the PNG compression and optimization result comparison between Kraken.io and CompressPNG.com

As noted CompressPNG is the clear winner but only by a couple of KBs. Over a very large site a couple of kilobytes could add up but overall I doubt many sites would notice the difference in load time. I will cover which option is best for you in the conclusion, but next is the JPG test.

JPG Compression Tools Reviewed

Using CompressJPG.com and Kraken.io I optimized several images to see how they would compare in terms of image file size before and after optimization. Here are the results:

A screenshot of the JPG compression and optimization results comparing Kraken.io and CompressJPG.com

Here the results were not nearly as impressive as the PNGs. This is likely because JPG optimization in most programs is quite decent already so there is less to improve upon. That said I would invite a more technical response  from anyone in the know on this subject.

And the Winners Are

Here are the results again in a single set of tables:

JPG and PNG compression and optimization results comparing Kraken.io and CompressPNG.com and CompressJPG.com

In conclusion the winner of the PNG optimization is CompressPNG.com and the winner of the JPG optimization is Kraken. That said between the two you have to weigh your options because one is a free tool and the other is a full-blown service provider:

WordPress Users
If you have WordPress then the obvious winner is Kraken because it offers a WordPress plugin that can automate not only reduces the file size of images as you upload them but it offers the ability to optimize all of your site’s existing images at once; which can lead to immediate page speed improvements – but at a cost. There is a monthly fee for Kraken’s service of between $9 and $39 for non-enterprise size businesses. This is a small price to pay for significantly improved image file size but I am intimately aware how $9 here and $20 there can add up to significant bills on a monthly basis.

If You Want a Free Service But You Have Larger Images
If your images are larger than 1mb then you cannot use Kraken.IO’s free web interface for to optimize your images so CompressPNG/JPG will be your best choice.

Your Site is Non-WordPress But You Want The Best Solution
If you want to optimize all of the images on your site the only choice is Kraken.io which, for a monthly plan will allow you to interface with Dropbox and have a large number of images optimized. It means after optimization you will still have to re-upload the images to your site to see the effect of your work but that is a small inconvenience for the benefits.

There Are Other Programs Available
I plan on testing these alternative image optimization tools which seem to have loyal followers soon:

  • JPEGmini (MAC & Windows): $20 and up to buy and it reportedly has phenomenal JPEG optimization capabilities which may very well be above those I reviewed. Here is a fantastic video review of how awesome this program is for JPEGs. It is a lossy compression system which technically loses some quality during the optimization but as you can see in the video review it is extremely difficult to see any degradation.
  • ImageOptim.com (MAC): this program uses lossless technology which will keep the image the same quality without exception while lowering file size. It is not going to make files as small as lossless technologies but it will definitely help you save on download time.
  • Smushit.com: this is a highly regarded free service by Yahoo which will optimize any images you throw at it. It is a part of the YSlow system for analyzing and improving site speed. Unfortunately I have never found it to match (not even close) the other options in this article. That said it is popular so I didn’t want it left out.

Need Help?

If you want to improve your site speed just drop me a note our contact page and we can setup a time to talk. ShelterSEO can help you to not only reduce image file size but all of the other aspects of your site which lead to slower load times. It is a bit of a science and oddly we love it.

With warm regards, Ross Dunn

PS. Yes, of course I optimized the images in this document:

A screenshot of the 3 main images from this article optimized on CompressPNG.com


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