1 June 2017

The Image Optimization Manual For WordPress

Images are a key part to engage visitors. In the context of the web where we all routinely skim and scan content throughout, successful content actively incorporates images among written content. Including an image every 75-100 words greatly boost SEO traffic. Images are a great way to communicate with your audience. However, there’s a downside we don’t often discuss: heavy images make for heave webpages.

Are you worried about the heavy images?

Image compression is key these days. For reference, in 2013 the average page was 1,2MB. Today, websites tested on our image optimizer are 1,7MB on average. Webpages keep getting heavier because of the images we use.

A Quick Guide To Image File Formats

You can save images in several file formats. The most widely used file formats online are PNG and JPEG. There are others out there but we found that the most popular format is JPEG. 90% of images compressed with Imagify are JPEGs.

  • JPEG – best for photographs or designs with people, places or things in them
  • PNG – best for images with transparent backgrounds
  • GIF – best for animated GIFs, otherwise, use the JPG format

You can learn about the difference between lossy and lossless image formats in one of our other blog articles.

WordPress and Images

Today, most websites are powered by WordPress. WordPress is a great CMS for a wide ranger of websites: photography websites, business websites, portfolios, blogs, e-commerce and more. However, WordPress creates quite a few versions of each image you upload. As a result, it is important to compress your images to maintain your WordPress’ load time. 

Even though WordPress offers a lot of benefits, it does not inform you when large image files are uploaded. The more heavy images are added on a website, the heavier it gets. This makes for slow load times. This isn’t good news for you, your visitors or your SEO rankings.

In this article, we’ll look at how you can optimize images for your WordPress website.

WordPress Creates Thumbnail, Medium and Large Image Sizes

WordPress generates different versions of images you upload. There are 3 predefined image sizes: thumbnail, medium and large. Each size has its own dimensions. Depending on the theme you use on your website, WordPress may be generating more image file sizes and dimensions. You can set the thumbnail, medium and large image sizes within WordPress.

Image Optimization Options

As a WordPress user, you can go about making your website images web-friendly in various ways:

  1. You can optimize images offline in an image editing program like Gimp or Photoshop
  2. Or, you can optimize images online via a tool
  3. Otherwise, you can optimize images via a script, a plugin or an API automatically

Sometimes, you need to resize an image by cropping it. For this, we can advise you to check out a great resource entitled “How to crop images like a pro“. If you need to crop an image, just remember 2 things: always work on a copy of an image, not the original and always maintain the aspect ratio, otherwise your images may look very weird.

Image Compression 101

Assuming your images are cropped the right way, resized to perfection and compressed for the web – you may still run into issues with WordPress. You may upload one image in your media folder but WordPress will be creating many more.

WordPress often creates three to five variations of each image in different sizes.

This is where image compression becomes important: it is a great way to optimize images once they are already uploaded on a website. Compression is the process of algorithmically removing information that our human eyes do not pick up in order to decrease image size. Image compression can be lossy or lossless. You need to pick the right type of image compression that allows you to strike the right balance between compression and quality.

Lossy Image Compression is often used for JPEG images. It helps generate an image with a much smaller file size but the quality may not always be of the best quality.

Lossless Image Compression allows you to keep your image data intact but the resulting images will be heavier than with lossy image compression. This type of compression is often used for PNG and GIF files.

Image Compression in WordPress

WordPress users may not know about this little fact: WordPress compresses images by default. For example, JPEG images are compressed at 82 percent when WordPress creates preview images. The functions.php file allows you to increase of decrease the level of compression used by WordPress. However, changing this built-in compression is not for beginners. We recommend you ask a WordPress developer to help you with this.

Aim To Enhance WordPress’ Image Compression

The most recommended way to handle image compression in WordPress is to make sure that it is done automatically. You should seek to enhance the existing image compression by using an image optimization tool with a powerful image compression algorithm.

The Benefits Of Using An Image Compression Tool With WordPress

If you use a WordPress image compression plugin or an API (it does the same thing minus the WP interface) you will be able to optimize images on the fly. This means that you won’t have to deal with compressing each image before you upload it; it will be done automatically within WordPress!

It means that you don’t have to worry about all of this, the tool will take care of it for you!

Case in point, Imagify helped make the web lighter by 5TB.

This represents more than 100 millions optimized in the span of a few months!

Do You Need To Compress Images On Your Website?

There are various ways you can tell if you need to compress images:

  • Have you used images you downloaded from Unsplash or another free image source? If so, chances are you need to optimize them as these images tend to be very heavy.
  • Have you uploaded screenshots you made without compressing them beforehand? Well, image compression is for you as well!
  • Is your website a few years old? A good rule of thumb is that you should optimize any images that is over 100 KB.

Careful though: some performance tools such as Google Page Speed may falsely report that you need to optimize your images to have a better load time. This isn’t always the case. There are multiple algorithms out there for image compression. Google Page Speed measures image performance using one type of algorithm, while most compression tools use another algorithm to get the work done. As a result, you may get a false positive.

Imagify, decrease the size of your images, increase the speed of your website: try it for free
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