I always thought that smush.it was the best website to re sample png images. I was wrong! If you want to compress images to reduce the size and retain the same quality than tinypng.com is the best one out of all online compression tools, that I tested. With compresspng.com being the best advanced tool where you can customize the color quantity to further reduce the file size. I have tested 8 online png compression tools, please read below for each individual reviews.
With the rise of mobile devices, it is now even more important to compress your images to the maximum, without loosing any quality.
When optimizing images you have two types of compressions which are lossy and losseless.
This type of compression will push your images to the extreme without changing a single pixel. Lossless option is perfect when image quality is the most important factor.
When you decide to sacrifice just a small amount of image quality (unnoticeable to the human eye), you will be able to save up to 90% (!) of the initial file weight. Lossy optimization will give you outstanding results with just a fraction of image quality loss.
Remember – since outcome is always file-dependent, sometimes you won’t be able to tell the difference between images with “lossless” and “lossy” compression.
I created a simple graph and saved it as a png image. The original image size is 93.4k.
Uploading to smush.it resulted the image to save 20% and reduced the total image size to 73.6kb. While I must note that there is a smush.it plugin for WordPress. As of writing this article, unfortunately smush.it has stopped you from allowing to upload hundreds of images in one go. You can now only upload images by selecting each image, one by one.
You can upload up to 20 images per compression when uploading to tinypng.com, after a quick upload the image returned, reduced by an impressive 70%, resulting in an image size of 27.6kb
This website is slow in processing but allows you to upload up to 20 images per compression, while more time-consuming the results are even better. With this online tool you can reduce the quantity of colors used. You can reduce the size of your images up to 90% without loosing to many colors. You are starting to see pixelation around the object corners. This of course is caused by the reduction of color transitions. In this test I have reduced the image color quantity to 8.
This is a terrible converter, it automatically compresses your png image to 4 colors, leaving a terrible quality result, and only saving 35%
While this website is highly focused on converting you into a paying customer (PRO), they don’t seem to produce a better quality version than the other free tools. I could not view the PRO edition. Don’t really like to enter my credit card details for a trail version. But from the results in the free edition, it’s not worth your time or money.
Unfortunately nothing impressive with the down sampling in this test.
I do hate it when web developers place buttons to close to advertising. Already a big fail. Anyway this is a png optimization test, not a web review. This website does not reduce the image size high enough.
This is another great site for compressing images, not as good as tinypng.com but it sure is heading the correct benchmark out of all the websites tested. I would rate this as the 3rd best one.
The top online compression tools are:
There are more ways to improve your site, by reading how to speed up WordPress.