ShortPixel Review: How to Optimize Your Website Performance Through Image Compression

Since 2014, more than half a million users have already tried ShortPixel’s excellent image optimization. Foreseeing how important web speed optimization would be in the future, the Romania-based company launched ShortPixel Adaptive Images, an extremely easy-to-use plugin that resolves all the warnings related to images that GTmetrix or Google PageSpeed Insights report in a few clicks. This improves your SEO and the loading speed of your website.

But how does the plugin do all that? Let’s find out in this detailed review of Shortpixel Adaptive Images (SPAI for short).

What Does ShortPixel Adaptive Images Do?

Here are the 4 major things that ShortPixel does:

• It serves the images from a CDN: ShortPixel Adaptive Images takes all the images viewed by the visitors of a website and serves them from ShortPixel’s CDN. What is a CDN? It is a Content Distribution Network. In simple words, it is a group of servers distributed around the world that contains copies of a specific website. Thus, any user will have good loading times, regardless of what country or area they are located in. By loading the images from ShortPixel’s CDN, what you are doing is increasing the loading speed of the page (because most likely the CDN loads faster than the average hosting provider, in addition to having servers all over the world) and saving some resources from the server, as the images won’t be requested from there but from ShortPixel’s CDN.
• It compresses the images: the images served from the ShortPixel CDN are optimized using ShortPixel’s powerful optimization algorithm, which offers 3 levels of optimization, Lossy, Glossy, and Lossless. More on that later.
• It serves adaptive images: that’s where the name of the plugin comes from. Say you upload an image and you add it on a page in its full-size version. The user who visits the page from a smartphone will not need to see the image in the same size as a user who uses a laptop. The plugin takes care of that, serving the images in the exact size that the device is requesting. Have you ever used GTmetrix and got the “Properly size images” error? It is complaining precisely about this. ShortPixel Adaptive Images gets rid of that message in a couple of clicks!

• It solves all the image-related issues you may need: besides compressing the images and serving them in the correct size, images still can be further improved in many ways. ShortPixel Adaptive Images takes care of that as well, and with a few clicks you can do the following:
  • Remove the EXIF information
  • Serve images in WebP format
  • Lazy-load images
  • Smartly crop the images
  • Exclude images from lazy-loading (useful to preload an image)

How Does ShortPixel Adaptive Images work?

Like we explained, every time one of the pages of a website is visited, ShortPixel Adaptive Images (SPAI) analyzes its code and replaces each original un-optimized image with the right-sized & optimized image. Each replaced image is served from the ShortPixel CDN.

SPAI does not touch any of the files on the server; SPAI optimizes the images on the fly, which means that if you want to return to the original images, you can simply deactivate them. This is the detailed process, completely transparent to all users:

1. A user visits a page containing images.

2. While the page is loading, SPAI looks for any image URLs on the code, for example:

3. After detecting an image URL, it sends that image to ShortPixel’s servers, which optimize it and store it on ShortPixel’s CDN. This step is done only the first time a specific image size is requested.

4. Then, SPAI replaces the URL with a new one, which points to the CDN containing the optimized and properly sized image:

5. The page finishes loading and the images have been served from ShortPixel’s fast CDN!

Installing And Setting up ShortPixel Adaptive Images

Installation

This is the easiest step, it is installed like any other plugin. This is the page you need to look for: ShortPixel Adaptive Images – WordPress.org

Setting it up

Onboarding wizard

If it’s the first time you are using ShortPixel Adaptive Images, you will now be redirected to the Onboarding Wizard:

This 4-step wizard will help you configure SPAI properly so all the images are served from the CDN optimized.

If, for example, you were already using SPAI and updated to the new version, you can restart the wizard by going to Settings > ShortPixel AI and clicking on the “Setup Wizard” button located on the top right Help menu:

Note that ShortPixel Adaptive Images does not require an API Key to start working (as opposed to ShortPixel Image Optimizer). You only need to associate your website/domain to your account so that your ShortPixel credits will be used, and that will be automatically done by the Onboarding Wizard.

After you complete the Onboarding Wizard, be sure to clear the cache of your site so the optimized images show up!

Settings

ShortPixel Adaptive Images is very easy to use, as it starts doing its magic right after activating and setting it up with the Onboarding Wizard; no need to click on any ON button or similar. However, SPAI also provides some settings to tune the image optimization. To access, just log in to your WordPress admin area and go to Settings > ShortPixel AI. We will go over the most important settings, so we are starting with the Compression tab.

• Compression level: here we can choose what level of compression we want our images to have.
  • Lossy is the best option for most users. The images processed with the Lossy algorithms are the smallest optimized images one can get. So, if the speed of your site is paramount and you want the best balance between optimization and picture quality, we recommend you to use Lossy optimization.
  • Glossy is the best choice if you still care about GTmetrix or Google PageSpeed Insights, but you believe that a slight loss of page speed is an acceptable compromise for top-notch image quality.
  • With Lossless, images are pixel-by-pixel identical to the originals, but they offer a smaller size reduction compared to either Lossy or Glossy processed files. If you want your images to remain untouched, then select this option.
• WebP support: The WebP format is an image format created by Google that gets excellent compression results with little loss of image quality. A quick example of how WebP behaves: we took a photo from the internet and using a random online JPG to WebP converter we went from 1.05 MiB to 344 KiB, a reduction of 67.93%, and the image quality is virtually identical! So, by checking the option “WebP Support” we tell SPAI that the image served from ShortPixel’s CDN should be in .webp format as long as the browser is compatible.

• Remove EXIF: The plugin allows to eliminate the “extra” information embedded in the image itself, such as the location, the author, the camera model, etc. This information is not usually necessary and removing it helps to reduce the weight of the image a little bit. Recommended to enable it.

Now we move to the Behaviour tab. Among many other tweaks, we can find the following:

• Smart crop: The plugin will identify cases when not all the image is displayed and crop it accordingly.
• Logged-in users: By default, ShortPixel AI serves and optimizes the images even if you are logged in. However, if you want to save some CDN traffic and credits, you can simply disable this option and then SPAI will only work for logged-out users (the visitors).
• LQ image placeholders: LQIP stands for Low-Quality Image Placeholders. They are very low-quality images (and thus very light) that will be loaded with the initial page load, and once the page is fully loaded, they are replaced with the full quality ones. That helps increase the perceived load time.

Next, in the Areas tab, we’ll find all kind of settings to tell SPAI what images should be parsed and optimized:

• SVG images (these won’t be optimized, only stored on the CDN).
• Images in CSS In this case, the CSS file itself will also be stored on the CDN.
• Images in JS blocks
• Images in JSON data

Finally, on the Exclusions tab, we find a few fields where we can exclude images from optimization:

• Excluded selectors: here we can write the CSS selectors we want SPAI to exclude from optimization.
  • If you write them in “Don’t lazy load”, such selectors won’t be lazy-loaded, but they will still be optimized and resized.
  • If you write them in “Don’t resize”, SPAI will optimize such images but not resize them.
  • If you write them in “Leave out completely”, SPAI will completely ignore them, with no optimization nor resizing.
• Excluded URLs: if you want SPAI to ignore some of the images by URL, this is where we exclude them, using regular expressions (to exclude all GIFs or all PNGs, for example) or paths (to exclude a single image, for example). The plugin includes a good explanation of how to use this field, make sure to check it out!

After all the settings are in place, be sure to check out the new Image Checker tool, a straightforward tool to check the status of the optimized images on any page of the site. Just visit any of your pages while logged in; on the Toolbar, you will notice the famous ShortPixel robot:

Click on that icon and you will turn on the Image Checker. A tag will appear for each image: “CDN” or “ORIGIN”. “CDN” means that the image is served optimized from ShortPixel’s CDN, and “ORIGIN” that it’s served from the server or, in other words, that ShortPixel Adaptive Images is not processing it.

Also, the cursor will change to a cross (⌖) and when we click on an image, we will get additional information and actions:

Prices And Plans

Before talking about pricing, we need to remember that SPAI works on the fly. It only processes the images if they are viewed at least once from the front-end. Until that happens, the image will remain unprocessed and therefore will not spend any credit.

Processing an image means smart-cropping (if chosen), resizing, and optimizing it. Once the image is processed, it is stored on the ShortPixel CDN servers and it can be served to everybody using the CDN traffic quota you purchased. As long as there is enough CDN traffic quota available, the optimized images will be served from ShortPixel’s CDN.

ShortPixel offers credits that are converted to CDN quota. The rule is simple: 5 MB of CDN traffic = 1 credit. Both one-time and monthly credits can be used to process images.

Monthly plans

• Free plan = 100 credits = 500 MB of CDN traffic = ~500 visits/month
• $4.99/month plan = 5,000 credits/month = 25 GB of CDN traffic = ~25,000 visits/month
• $9.99/month plan = 16,000 credits/month = 80 GB of CDN traffic = ~80,000 visits/month
• $29.99/month plan = 55,000 credits/month = 275 GB of CDN traffic = ~275,000 visits/month
• $99.99/month plan = 220,000 credits/month = 1 TB of CDN traffic = ~1,100,000 visits/month

One-time plans

• $9.99 – 10,000 credits = 50 GB = ~50,000 visits
• $19.99 – 30,000 credits = 150 GB = ~150,000 visits
• $29.99 – 50,000 credits = 250 GB = ~250,000 visits
• $99 – 170,000 credits = 850 GB = ~850,000 visits
• $249 – 500,000 credits = 5 TB = ~2,500,000 visits

Example: Say you own a medium website with 5000+ images that gets 10,000 visits per month.

A monthly plan of $4.99/month will allow 25 GB of CDN traffic, and this, from our tests, translates into about 25,000 visits per month.

Learn more about plans and pricing here.

Is It Worth It?

Taking into account that the heaviest part of a website is always the images and that every extra second that the website takes to load results in lost users and conversions, it is definitely worth it. It is an install-and-forget plugin, and in case you want to return to your original images, you can simply uninstall it and that will do the trick.

In addition, their support team is wonderful and dozens of users can vouch for that on wordpress.org.

It’s a highly recommended plugin that helps improve your website’s speed, increases your position in Google and your visitors count. And if you combine it with good quality hosting such as Cloudways, the results will be even more exciting.

We hope this review of ShortPixel Adaptive Images will help you make your site super-fast!

Mansoor Ahmed Khan

Been in content marketing since 2014, and I still get a kick out of creating stories that resonate with the target audience and drive results. At Cloudways by DigitalOcean (a leading cloud hosting company, btw!), I lead a dream team of content creators. Together, we brainstorm, write, and churn out awesome content across all the channels: blogs, social media, emails, you name it! You can reach out to me at [email protected].

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