Compressing images: an absolute must

From saving storage space to minimizing download and upload times, there are many reasons to decrease the size of an image file. Compressing images has an especially positive effect on website loading times. This is because large image files require longer loading times, which negatively affects search engine ranking.

But how can you compress images while also avoiding quality loss? And what resources can be used? Websites designed specifically for this task make minimizing image sizes a manageable feat. There’s also a large selection of offline options. We’ve compiled an overview of the topic:

Why should I compress my images?

These days, high-resolution images and photos are common. In digital photography, pixel counts and file sizes are increasing. Whether you’re uploading images to your website or just sending them by e-mail, it’s always important to keep file sizes to a minimum. Remember, the smaller the file, the less time it takes to transfer.

Those who manage a web presence should try to make sure that the image’s data volume is no bigger than necessary. Long loading processes are not only irritating for the website’s visitors (especially mobile visitors); they also affect your site’s visibility on search engines. Extensive loading times are negatively rated by Google, causing your website to rank lower in the search results. An SEO-friendly site needs images of reasonable file size.

The right data format for online images

Before putting your images online, you should check the image file format. Not every graphic format is suitable for internet use. Here are three format types that can be used:

  • JPG/JPEG: JPG is one of the most commonly used image formats. It can display 16.7 million colors and boasts robust compression rates. Compressing with JPG, however, is most often associated with quality compromises. Some losses are so small, though, that the naked eye isn’t able to pick up on them. Furthermore, transparent areas can’t be displayed in this format. JPGs are therefore mostly used for saving photos or photo-like graphics, particularly those with lots of different colors and stark contrasts.
  • PNG: the PNG format can depict between 256 (PNG8) and 16.7 million (PNG24) different colors and be used online. Unlike JPGs, this format can be compressed without any sacrifices to quality. The required data volume, however, is quite large. PNG files are well suited for saving graphics, logos, and texts. Images with few colors can be compressed into files only a fraction of the image’s original size. PNGs can also depict format transparencies. This is why this file type is also often used for image files with transparent planes that don’t completely cover the backgrounds.
  • GIF: despite the relatively small range of colors they’re able to display, GIF files have proven to be quite popular for internet use. This is because GIF formats are able to depict animations. Due to their less-than-generous color range, GIFs are generally used to depict website navigation elements or simple graphics. They also support transparencies.

Image compression with freeware

Pixelated images on websites convey an amateur level of competency and should thus be avoided. However, high quality images require robust data volume and therefore draw out a site’s loading time. Current image compression programs are able to reduce losses of quality to such an extent that most changes are unnoticeable to the naked eye. Furthermore, there are a range of free software options on the internet. Many programs boast more than just high-quality functions, they’re also easy to use.

Caesium image compressor is a tool for Windows that allows users to compress their own images. There’s also a host of other freeware versions available. ImageOptim, an alternative for Mac operating systems, has a drag and drop feature. PNGGautlent can be installed on Windows PCs and has another special feature as well: PNGgautlent automatically converts files like JPG and GIF into PNG files once they’ve been compressed.

Compressing images online via the browser

If you don’t want to download and install a program, you can also compress your image files online. Websites like or optimizilla offer free browser programs that let users reduce the data volume of PNG and JPG files (but only up to a limited number). You can compress images online by uploading image files via the browser tool and then downloading the compressed version.

Whether directly on your desktop or with the help of an online tool: compressing images for your website doesn’t need to be a difficult task. A higher page speed (website loading time) is rewarded by search engines in the form of a better ranking.