Google, like your blog visitors, is more and more sensitive to the loading speed of web pages . It is important when browsing on a computer but it simply becomes essential when we are on a mobile. One of the elements that weighs down a web page the most are images.
I have already given you tips on how to reference and optimize images on the blog, but there are also WordPress plugins that can help you lighten the weight of the photos or illustrations you post on your blog.
Among them, the Short Pixel plugin . It caught my eye because it is very easy to use and works on any type of hosting. Indeed, image optimization requires certain “features” that are not available from all hosting providers.
If you’ve tried plugins like WP Smush without success, Short Pixel may offer a good alternative!
Install and configure the Short Pixel plugin
Sign up for free by entering your email address on the Short Pixel website . If you use this link instead of installing the plugin directly, you will in principle be able to optimize 200 images per month for free instead of 100 …
You will receive by e-mail a code of around twenty characters (letters and numbers). This is the API key, which will allow your site to “communicate” with Short Pixel to optimize images.
Then, in the Extensions> Add menu of WordPress, find “Short Pixel Image Optimizer” and install the plugin .
After enabling it, you can access the settings by going to Settings> ShortPixel.
Copy and paste the API key that you received by email in the plugin settings and click on “Validate”.
Short Pixel offers few settings, making it an easy extension for beginners to use.
The General tab of settings
Beyond the API key, this is where you can set the type of compression you want for your images:
- Lossless Compression – The image is compressed without any loss in quality but often remains a little heavier than desired.
- Glossy Compression – The image is compressed with a slight loss of quality, most of the time invisible to the naked eye. It’s a great choice for anyone who features a lot of photos on their blog.
- Lossy Compression – This is a very powerful compression but since it can affect the quality of the images a bit more, it requires testing beforehand to see if it does not affect the visual rendering too much.
You can then decide if the compression should be applied to the thumbnails (“Also include thumbnails”): if you check the box, ShortPixel will optimize both your large format images and the thumbnails. If you use the plugin in free version, it is limited to 100 images per month and the quota can quickly increase if you include large format AND thumbnails: you can then uncheck the box to optimize only large images.
At the beginning, I advise you to check the “Image backup” box when using the plugin to optimize already existing images . This will create a backup of the original images (before optimization). Like this, if you are not satisfied with the performance of Short Pixel, your images lose too much in quality, you can easily recover the original images.
Of course, if you see that the optimization is going well, you can turn off the option to avoid storing two sets of images unnecessarily (the original images and the compressed images).
Except in special cases, I advise you to check the “Remove EXIF” box in this settings tab. EXIF data is information added to the photo, which gives details about the date and time of the shooting, the settings used, copyright, etc.
Very often, it is not useful to keep these data for use of images in standard format on the web… unless you are a photographer for example and want to allow readers to consult the settings made.
Finally, you have a “Resize large images” option: it allows you to automatically resize all the images that exceed a certain size . For example, if you are used to uploading your images without resizing them, you might have files that are 4000 × 5330 pixels. Short Pixel can automatically resize them to a smaller size.
Resizing maintains the proportions of the original image.
The advanced settings of the ShortPixel plugin
These settings are only for expert users.
The Additional media folders option allows you to optimize images that are not in the WordPress media library but elsewhere on your server (for example, images in your theme’s folder). You just have to fill in the file in question here.
The Convert PNG images to JPEG option allows you to automatically try to convert all the images uploaded in PNG format to JPEG format, if they do not have a transparent area. You can also force the systematic conversion of PNGs (even those with transparency) by checking the “Force conversion of images with transparency” box.
The CMYK to RGB conversion option concerns the color of the photos: when printing a photo on paper, its colors are generally defined in “cyan-magenta-yellow-black” (CMYK in French, CMYK in English because “black” is translated by “key”), we speak of four-color process. On the web, we don’t use CMYK but “red-green-blue” (RGB in French, RGB in English) because it corresponds to the way a screen displays colors, by the synthesis of these three colors.
This option allows you to convert the image colorimetry mode.
We then enter into options that directly target the performance of the images.
- Use of the WebP format – The WebP is a very powerful optimized format, which you can activate with a single click by checking the box “Create also WebP versions”. WebP is not yet supported by all browsers, so it comes on top of the more traditional image format you upload (and all images need to be re-optimized with ShortPixel to generate their WebP version). It also requires the addition of a specific piece of code, which Short Pixel can handle for you if you check the “Generate WebP markup” box.
- Retina images – If you generate Retina images (via a plugin for example), check the box to have ShortPixel optimize them too.
- Unlisted thumbnails – Some plugins create thumbnails of images that are not listed by WordPress. Checking this option allows Short Pixel to optimize them anyway.
- PDFs – By checking the box, the plugin will also try to optimize PDFs if you post them.
Finally, the plugin offers other administration options:
- Exclude patterns – You can prevent certain images from being optimized by using a pattern system, which should be written in this form: “type: value”. The type can be a name, a file path, or a file size (size). For example, if I write “name: notuxedo”, I exclude from optimization any images that have “notuxedo” in their name. The plugin creator gives a lot of useful explanations on this page if you want to use the option.
- HTTP AUTH credentials – If your site requires a username and password to connect (private blog reserved for those around you or your company for example), you can enter the connection information here.
- Front-end process – If people can post photos on your blog, this option also optimizes the images they submit.
- Optimize media on upload – Checking this box will systematically optimize the new images you upload . If the option is not activated, you will have to manually launch the image optimization.
- Exclude thumbnail sizes – You can exclude certain sizes of image thumbnails from optimization. For example, for my part I exclude the optimization of very small thumbnails because I don’t want to touch my ShortPixel “quota” for such small images.
ShortPixel Image Optimizer finally offers two additional tabs. One is for users of the Cloudflare service , who can enter a few parameters to facilitate the integration of Cloudflare and Short Pixel.
The other is a statistics tab , which takes stock of the use of your image quota, the disk space and bandwidth saved thanks to the plugin, etc.
When you have finished your settings, don’t forget to save them by clicking on “Save Changes”.
Optimize existing images
Once the plugin is configured, it will optimize the images you upload. But you can also optimize the images already present on your blog . The extension works on JPG, PNG, GIF files as well as PDFs.
You can optimize an image individually by going to the Media> Library menu and clicking on the button in the column to the right of the screen. You can also batch optimize images by going to Media> Bulk ShortPixel.
The limitations of the Short Pixel Image Optimizer extension
ShortPixel is really a well-designed plugin but the free version is limited to 100 images per month . To optimize more images , you have two possibilities:
- Buy Credits – You can then use them anytime you need.
- Get a subscription – This will give you a higher optimization quota each month than in the free version but if you don’t use the credits they will expire at the end of the month.
In any case, your credits can be used on one or more sites , which I find very practical. You can consult your remaining credits at any time in the Settings> ShortPixel menu, “Statistics” tab.
I used ShortPixel for a long time on the blog because the other extensions did not work, I still use it on my travel blog because this extension has evolved to offer innovative features like the WebP format that I recently decided to hate. On No Tuxedo, I tend to settle for the JPEGMini Pro software (desktop software) before uploading the images