What is the best image compression software

Find the best tool for compressing PNG images


Whether you are building a website, posting an online photo gallery, or want to share your favorite pictures on a social network, the need to compress high quality images is vital. Any image that is smaller in size loads faster on a web page, fits more easily in an email message, and is faster to travel across the Internet.

Compressed images can speed up the overall page load time of your site, and this is very important if you want to create a high quality webpage that won't annoy visitors because the images take so long to load!

There's a whole laundry list of image compression apps out there. I chose to focus on four of the best products available to see how effectively they compress PNG images. I chose the PNG image file format because it is fast becoming the most common format for web design for several reasons, as we discussed in a previous article on file formats. Know when to use which file format: PNG vs. JPG, DOC vs. PDF, MP3 vs. FLAC Know which file format to use when: PNG vs. JPG, DOC vs. PDF, MP3 vs. FLAC Know the differences between JPG and PNG or MP3 and FLAC? If you don't know what file formats to use, let us guide you through the differences. Continue reading . The only disadvantage of PNG is that the file size is usually larger, and therefore file compression. How does file compression work? How does file compression work? File compression is at the core of how the modern web works, one might argue, because it allows us to share files that would otherwise take too long. But how does it work? Read More

In this article, I'm going to test four PNG compression apps, provide the results for each case, and then make a conclusion which is the best.

Testing the image compression software

In this article, I'm not just sticking to desktop software. Anything is possible and I mainly focused on the top compression apps recommended here on MakeUseOf. For starters, here is the picture I used in each of the compression tests. The source image was a 1121-by-855-pixel image of a lighthouse shining in the golden light of the setting sun.

As you can see, the picture has a lot of color, contrasting shades of dark browns, greens and lots of light colors. Any compression problems are sure to crop up quickly in such an image.

Test IrFanView

I started with the Screen Capture application How to Take a Screenshot & Batch Process Images with IrfanView How to Take a Screenshot & Batch Process Images with IrfanView Read More It happens that IrFanView also acts as a compression module when you save the captured image.

The way it works, when you save a PNG file, you can set the compression level. When I usually save image files, I choose a compression of 5 so that it reduces the file size, but I still get a nice, clear image.

This isn't based on any evidence, just a suspicion that if I crank it up to the maximum compression of 9, it makes the picture really bad. However, since my goal is to test the best that each application can do, I went with maximum compression. The result was a file almost half the file size of the original image.

Surprisingly, there was no noticeable decrease in image quality as far as I could see. Incidentally, this is an important distinction. Most of the effects of file compression are invisible to the naked eye, or at least to the untrained eye. A person with a magnifying glass, or probably even a well-trained photographer, could point out the subtle flaws caused by the extreme compression. Still, I was pretty impressed with the quality and wouldn't hesitate to use it on my own website.

Compression with PNGGauntlet

Another popular image compression tool that Craig calls the no-loss compression tool is PNGGauntlet. This is a desktop app that allows you to place the image file (literally grabbing and moving the file with your mouse) into the PNGGauntlet window. It's that simple. Make sure the compression level is set on the OptiPNG tab.

For this test, of course, I set the compression to the maximum level and then to "Optimize!" Clicked to see what the results would be. Surprisingly, PNGGauntlet was a bit better than IrFanView with the compression, shaving an additional 18kb from the final file size.

Again, no visible effects from the compression process, which really surprised me. Indeed, this type of image might actually work best when compressed, while an image with more large, solidly colored areas would be worse. I'm not sure, but as far as I could tell, both applications have done amazing tweaks so far with no noticeable quality effects to the image, while reducing the file size by about half.

Try Kraken Online Tool & Browser Add-On

Another popular image compression tool is Kraken, a fast online image enhancement tool. 10 Free Online Batch Image Tools to Resize, Convert, and Optimize 10 Free Online Batch Image Tools to Resize, Convert, and Optimize Photos Process in Very Little Time. We introduce you to the best batch resizers, optimizers or converters available online. Read more from Hammad. You can download it as an add-on for Firefox or Chrome, which makes it one of the most convenient ways to compress images while on the web.

You can upload images to perform the compression on the Kraken website. Unfortunately when I tried to upload my large 2mb file the system blocked it and told me the file size was too big.

This results in Kraken no longer running for "best PNG compression tool" as any compression tool should allow extra large file sizes as people mostly try to make the file size smaller. It seems ironic to limit the size of the upload file like this.

Testing the CompressPNG online tool

Another interesting aspect that we found earlier to be an easy-to-use image compression service is CompressPNG. This is a really cool online tool that doesn't require you to sign up for an account. You just visit the website, upload the file you want to compress, and you're good to go.

What is special about this tool is that it is about the number of colors that are used in the image. Many high resolution images can use thousands or at least many hundreds of colors in a single image. What CompressPNG does is that it actually combines many of the same colors and uses a single substitute color for those that go unnoticed unless the "Colors" setting is set to something very extreme, like 2 colors.

Well, that was an image compression technique that set your socks apart from the rest. By using this "colors" approach and setting the colors halfway, I was able to find that CompressNow was able to drop the nearly 3MB image down to almost 400KB. It's just phenomenal, and the finished product is an image that looks identical to the original in every way.

Which image file compression tool should you choose?

So you can see that not all image compression apps are created equal. That's why it's an important first step to check out the many testimonials on these apps here at MakeUseOf before deciding which application you want to use. Just because software has a lot of bells and whistles doesn't mean it's the best of everything. In this case, CompressPNG, a simple online app, outperformed much more powerful desktop compression programs.

What compression tools do you use to shrink the size of your photo without sacrificing image quality? Feel free to offer your own suggestions and favorite apps in the comments below.

Photo credit: Little Flower via Vikysaurus / Flickr