Have you ever tested your website/blog on Google page speed insight? I was did it before with one of my blog, and one of the suggestion given by the page speed insight is to "compressing bla..bla.. image can save bla..bla..". So in this post I will share how we can compress image files to make our site/blog load faster.

Page Speed Insight is a free tool by Google to measure how well site optimization has been applied on our website to make it load as fast as possible.

Compressing image is a means to how to reduce image file sizes without any noticeable quality loss and preserve transparency on your png image.

For me, compressing an image before uploading and display it on my site/blog is a high priority thing. I mean, let's think logically.

Say you have an PNG file with 1 MB size, but you can compress it to reduce the size to 500 kb and then you upload it to use it in your blog post. Say there are 1000 people read you blog post, so we are already saved amount of bandwith: 500 kb x 1000 = 500000 kb = 500 MB. Wow, 500 MB is not a small amount of bandwith/data, and we even haven't multiple it by days, months, years.

From the example above, we get benefit of time and money not only for our visitor but also we as a webmaster/blog because less bandwith means less cost to pay for our hosting, less cost means less work and more spare time. Moreover image compression on our website/blog is one of a good SEO practice to boost our site ranking in search engine.

If we think it more deeply from many things we can save by compressing images on our website/blog, it is similar to green earth movement "reduce the usage of plastic bag". Then compressing image files on our website is a green (errr... what color does internet look?) movement to the internet, don't you agree?

Thanks to the developer who bring us advanced image compression algorithms, we can reduce that 1 Megabyte photo into 500 kb or even less without your eyes will notice the differences between them.

There are many services and applications have been created for image compression. You can choose to use online service on the websites or compress the image directly on your devices using application/softwares.

Image compression free service on websites

There are a lot free services we can choose from to compress our image files online. There are TinyJPG, CompressPNG, Optimizilla and dozens more website who offer free image compression service. But after tried many different websites, my best choice falls to Optimizilla.com

Optimizilla has a simple and neat user interface. User can preview the result and change the compression setting on the fly. It also support for multiple image file upload at a same time so it can save our time.

Sample of PNG image compressed at Optimizilla:


Original (417 kb)

Compressed (167 kb)

Image compression using application/programs directly on your device

Image compression directly on our device can be more complicated (at least from what I experienced). Some app/program are good on compressing JPG/JPEG but poor on compressing PNG image, and some of them is vice versa.

Image compression program/software on Windows

On Windows, I can't seem to find a perfect program that good on compressing both JPG/JPEG and PNG image files. So right now, I depend to these 2 program/software to compress images on my Windows tablet:

  • FileMinimizer Pictures
    FileMinimizer is a program that able to compress almost every important files and documents type to your computer. FileMinimizer Pictures is one of the free program of FileMinimizer with limitation of image compressing only. As my experience used it, FileMinimizer Pictures did a great job on JPG/JPEG compression, but sucks in PNG.

    Sample of JPG image file compressed using FileMinimizer Pictures on my Windows tablet:


    Original (123 kb)

    Compressed (54 kb)

  • PNGQuant
    PNGQuant is the name of the project that build a lossy PNG image file compressor algorithm/binary. So PNGQuant doesn't have User Interface, but we can download the available GUI programs for Windows, macOS, etc. that uses PNGQuant on the website.

    Sample of PNG image files compressed using pngyu, one of GUI program that use PNGQuant on my Windows tablet:


    Original (233 kb)

    Compressed (97 kb)

Images credit: www.pexels.com