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WordPress Image Optimization Plugins that Actually Work

Maintaining a successful website is no easy task. Aside from writing compelling content, distributing it on prolific channels and boosting its potential outreach, your site needs to deliver the best user experience, as fast as possible, so that you can both attract new visitors and keep the current ones coming back for more. There are a lot of technical issues that need to be taken into consideration, but there is one that stands out every time, that infamously succeeds in pushing away your visitors: slow load times.

There are a lot of factors which can impact your load times and a lot of optimizations you can implement to prevent that from happening. You can choose from a wide array of options: opt for a fast theme, install a caching plugin (we’ve developed our own caching mechanism to help you out), install clean plugins and keep them updated, optimize your database, delete old posts revisions and the list can go on and on. However, the first thing you need to take into consideration is optimizing your images. Images are greatly surpassing in size the plain text, but as the old saying goes, “a picture is worth a thousand words”, hence the visual-first trend across the web that needs a supporting solution.

Image optimization implies reducing the file size of your images as much as possible, without sacrificing quality, so that your page load times remains low. There are a lot of image optimization plugins out there, so we have chosen a few ones that do a great job at optimizing images and that are 100% compatible with our platform.

All the selected plugins contain the following basic features:

  • Optimize JPG, PNG, GIF  & PDF formats
  • Automatically process new images on upload. After installing and enabling the plugin, every JPG, PNG, and GIF you upload will be automatically optimized, using the default compression method.
  • Optimizes thumbnails. Image thumbnails created by WordPress during the uploading process, you can deselect thumbnails from compression.
  • Individual and bulk optimization
  • Lossy and lossless compression
  • Establish maximum resolution for images
  • Capable of removing EXIF data
  • Saves a backup of every image you upload. Automatically storing the original copy of the image makes it easy to restore anytime you need it.
  • Custom folder optimization
  • Retina support.

In order to test the plugins in terms of actual compression and quality of images, we have taken some photographs at our awesome Presslabs headquarters, using three JPEG images and one PNG image:

  • test1.png – 1.5 MB
  • test2.jpg – 876,3 KB
  • test3.jpg – 908,1 KB
  • test4.jpg – 954,2 KB

ShortPixel

ShortPixel not only scores well when it comes to compression, but it also has a nice interface. ShortPixel is entirely compatible with our platform, and their on point support team has helped us in solving any issues.

1.1 Installation time

original picture ShortPixel_intallation.png

As the name implies, it’s easy to install—simply search it in the WordPress plugins, install it and activate it. Like most of plugins, it requires an API key. If you want to set up the ShortPixel plugin, you’ll be prompted to enter an API key during the activation process, which is provided for free by signing up with your email to their subscription list and doesn’t require any additional information.

1.2 How easy it is to use

ShortPixel comes with an intuitive, easy to use interface.

ShortPixel_settings.png plugin ShortPixel

Each optimization option comes with a short description to help you in the process of choosing the best settings to optimize your images. By default, lossy compression is enabled, along with thumbnails optimization, image backups and the removal of EXIF tags. There is also a default image resize feature that will resize the images for you.

To bulk optimize your images, you can use the bulk optimization tool either directly from the ShortPixel Settings ( the “Save and Go to Bulk Process” button ) or from the Media library -> Bulk ShortPixel.

bulk optimization picture ShortPixel plugin WordPress

Here you can visualize details about the images to be optimized:

  • Number of original images
  • Number of smaller thumbnails; you have the possibility of deselecting thumbnails from compression; be aware that the thumbnails also count up to your total quota of images (in case of a free account you can optimize 100 images per day)
  • Number of total images, thumbnails included
  • Already optimized originals and already optimized thumbnails
  • Total images to be optimized. Shortpixel is the only one from our list that offers the possibility to bulk restore the images from the media library.
  • Individual images can be compressed by opening your Media Library in the List View format, where each file will appear with an individual Optimize Now button alongside it.

Plugin ShortPixel_image

For each compressed image you can see the compression method used (lossy, lossless or glossy) and how much it was reduced. You can also compare the optimized image with the original one, you can re-optimize it with another image compression method or you can easily restore the original image.

Optimization with ShortPixel The original picture vs the optimized picture

You can also bulk optimize selected images by simply selecting the images you want to optimize or reoptimize from the Media Library, and then select the action you want to perform from the Bulk actions drop-down.

Shortpixel also offers statistics regarding average compression files and saved disk space, as well as details regarding your Shortpixel plan: number of images processed this month, remaining images in your plan, the total number of processed files, your backup folder size (which can be emptied if you wish so).

ShortPixel_stats

1.3 Other Features

  • Optimizes PDFs and generates free WebP versions of the images. Besides compressing images that reside in the media library, the plugin also compresses images from galleries, like NextGEN or those added via FTP.
  • The glossy JPEG compression feature is sure to delight photographers.
  • No file size limit
  • Your free quota & paid quota are treated separately. This way you always have 100 free image compressions. Yay!
  • PNG to JPEG conversion
  • CMYK to RGB conversion
  • Exclude certain images from being optimized, based on patterns
  • HTTP AUTH credentials for sites that are not public
  • Support for Working with Cloudflare.

1.4 Photo quality/ optimization

Comprassion_ShortPixel

Quality comparison:

Original Original image
Optimized Optimized image
Original 1,5 MB - Optimized 629,4 KB
Original Original image
Optimized Optimized image
Original 876,3 KB - Optimized 69,5 KB
Original Original image
Optimized Optimized image
Original 908,1 KB - Optimized 72,4 KB
Original Original image
Optimized Optimized image
Original 954,2 KB - Optimized 85,4 KB

1.5 Maintenance

This plugin is updated on a regular basis & has 90K+ active installs with a 4.5-star rating.

1.6 Limitations

The free account allows you to reduce the sizes of 100 images and thumbnails per month. If you need more image optimization credits, you can purchase monthly and one-time plans according to your needs, as well as earn extra credits from referring new users to the service.

If you exhaust your free image credits, ShortPixel will stop optimizing. You can either wait for the next month’s quota when your plan will renew, or change your plan.

1.7 Pricing

ShortPixel comes with 100 free credits/month and additional credits can be bought with as little as $4.99 for 5,000 image credits. They offer monthly pricing plans, one-time plans and also the possibility of dedicated servers. The monthly plans start with as little as $4.99 for 5,000 images and the one-time plans with $9.99 for 10,000 images. The latter is a great choice if you wish to bulk optimize the images you have in your database. With each purchase, the one-time plans will add up to your quota.

Imagify

2.1 Installation time

It’s really easy to install, just simply search it in the WordPress plugins, install and activate it. A message showing you the steps for configuring your account pops up immediately in the plugins section.

Imagify_optimization_plugin.png

In the Settings section -> Imagify you can simply request an API key by providing your email address. You will receive an email containing both your API key and Imagify account credential shortly.

Imagify_optimization2 Imagify_isntallation2.png

You need to enter your API key where specified, and your account is now all set up.

2.2 How easy it is to use

Imagify comes with a nice interface, allowing you to configure the settings for each optimization level: normal, aggressive or ultra. The normal level uses a lossless compression, whereas the aggressive and ultra ones use the lossy compression. Each option is accompanied by a short description to help you decide if you need the setting or not. The general settings allow you to set auto-optimize images on load, backup original images and keep EXIf data.

Imagify_installation3.png Imagify optimization plugin

The optimization settings allow you to set a maximum pixel’s width and select the thumbnail dimensions to be optimized, as well as select custom folders for optimization.

Imagify_settings.png
You can easily spot your account type, which in this case is the free one. One great feature offered by Imagify is calculating what kind of plan you need, correlating with the total number of original images that have been optimized.

Imagify pricing plans imagify_plans.png
You can use the Bulk Optimization to optimize all the images on your site from Media -> Bulk optimization. The images will be optimized using the last compression method you saved from the Imagify settings page, which is by default the aggressive one, which offers the best compression while also keeping an unnoticeable photo quality.

Imagify bulk optimization Imagify_bulkoptimization.png

You can also optimize images individually from the Media Library. After an image is optimized, you can see details about the level of optimization, overall saving, the old and new file sizes, as well as the number of optimized thumbnails. You also have the possibility to reoptimize each image using another level of compression or restore the original image.

imagify_optimization_image.png

From the bulk action drop-down, you can bulk restore images to their originals, as well as restore individual images. You also have the possibility to compare the optimized version with the original one:

image compare imagify_compare.png

2.3 Other features

Imagify offers only the basic features presented at the begging of the article, grouped in three levels of optimization: normal (lossless), aggressive (lossy) and ultra (lossy). These settings are more than enough for basic optimization needs.

2.4 Photo quality/optimization

The photos optimized with the aggressive level:

Quality comparison:

Original Original image
Optimized Optimized image
Original 1,5 MB - Optimized 636,5 KB
Original Original image
Optimized Optimized image
Original 876,3 KB - Optimized 321,4 KB
Original Original image
Optimized Optimized image
Original 908,1 KB - Optimized 340,8 KB
Original Original image
Optimized Optimized image
Original 954,2 KB - Optimized 395.3 KB

The photos optimized with the ultra level:

imagify_compression2.png Photo optimized with ultra level

Quality comparison:

Original Original image
Optimized Optimized image
Original 1,5 MB - Optimized 292,8 KB
Original Original image
Optimized Optimized image
Original 876,3 KB - Optimized 274 KB
Original Original image
Optimized Optimized image
Original 908,1 KB - Optimized 291,6 KB
Original Original image
Optimized Optimized image
Original 954,2 KB - Optimized 342,9 KB

2.5 Maintenance

This plugin is updated on a regular basis & has 100K+ active installs with a 4.5-star rating.

2.6 Limitations

The free account allows you to optimize for free 25MB of images (about 250 images) every month and you will receive a 25MB bonus upon registration. Also, on the free account, you cannot optimize images greater than 2 MB. With a free account, once your quota is reached, you cannot optimize new images before renewal. With a paid account, you will be charged according to additional GB pricing of your subscription.

2.7 Pricing

Imagify offers free accounts, where you can optimize for free 25MB of images every month and you will receive a 25MB bonus upon registration. It includes monthly plans starting at $4.99 for 1GB of data per month, which they approximate covers for 10 000 images. Imagify also offers one time plans, starting at $5.99 for 500MB of data (approx. 5000 images).

EWWW Image Optimizer Cloud

For security reasons, the Ewww Image Optimizer is banned on our platform, since it requires the exec function, which is blocked by us. We recommend using the EWWW Image Optimizer Cloud, which offers a cloud optimization feature, instead of the optimization process taking place within your own servers.

3.1 Installation time

To install EWWW Image Optimizer Cloud, search it in the WordPress plugins section, install and activate it. Like most other plugins, it requires an API key. Here it gets a little trickier since the Cloud version of EWWW Image Optimizer does not offer a free account possibility. They charge based on how many images you’re processing per month (thumbnails included), with a small fee for the chosen plan. By subscribing to the Meteor Monthly plan, the fee you have to pay is $0.99 and you get 500 free credits upon registration, this means you can optimize for $0.99 500 images or thumbnails, afterward you will be charged with $0.003/ image.

Pricing plan EWWW Image Optimizer eww_pricing.png

Upon registration, you will receive an email with your API key, that you need to enter it in the Settings section of the plugin.

EWWW Image Optimizer installation eww_installation

3.2 How easy it is to use

Ewww Image Optimizer Cloud offers more complex settings, which results in a more intricated interface. This can seem overwhelming to a user who merely needs basic image optimizations, but you can use the default settings for basic optimization needs. The lossless method is enabled by default, so be aware of changing it to the lossy one if you need better optimization. Also, the default settings do not include any resing option regarding larger images.

EWWW Image Optimizer Cloud ewww_settings.png

ewww_settings3.png EWWW Image Optimizer Cloud Settings

To bulk optimize your images, go to Media -> Bulk Optimize.

EWWW Image Optimizer Cloud Bulk Optimize ewww_bulk_optimize.png

On the right corner are displayed the image credits you have left. If you surpass your credits, you will be charged with $0.003 / image. You can visualize the optimized images or scan for unoptimized images, which will tell you how many images will be optimized, and you can start optimizing them.

ewww_bulk_optimize2.png EWWW Bulk Optimize

You can stop the process, resume it or reset it at any time during the optimization. You can also optimize your images individually from the Media Library. For this purpose, you have an “Optimize now” button for each image that has not been optimized and the possibility to restore the original image for each optimized image. Keep in mind that EWWW Image Optimizer Cloud only keeps the original images for 30 days, so after this period, you won’t be able to restore your images anymore.

ewww_individual_optimization.png EWWW Image Optimizer Cloud-Individual Optimization

You can also reoptimize your images, if for example you change your optimization settings, or visualize details of the optimized images and thumbnails.
EWWW Image Optimizer Cloud- Optimization detalisewww_optimizing_details.png

3.3 Other features

  • No file size limit or speed limit
  • Override the default WordPress quality JPG level of 82
  • Parallel optimization
  • Scheduled optimization
  • With ExactDN support, images will be automatically resized to fit the page and device size. ExactDN also enables automatic WebP and Retina images when needed.
  • Enable JPG to PNG conversion, PNG to JPG and GIF to PNG
  • WebP Settings.

ewww_settings2.png EWWW Image Optimizer Cloud settings

ewww_settings4.png EWWW Image Optimizer Cloud Conversion Settings

ewww_settings5.png ewww image optimizer cloud-WebP settings

3.4 Photo quality/ optimization

ewww_compression.png EWWW Image Optimizer Cloud- Compression

The default Ewww Image Optimizer Cloud setting for PNG images is set to a lossless compression. This is the reason the PNG images was reduced by only 4.1%. Changing the PNG compression to lossy, the png image is reduced with 59.1%, which is a far better compression.

Quality comparison:

Original Original image
Optimized Optimized image
Original 1,5 MB - Optimized 1,4 MB
Original Original image
Optimized Optimized image
Original 876,3 KB - Optimized 204 KB
Original Original image
Optimized Optimized image
Original 908,1 KB - Optimized 233,3 KB
Original Original image
Optimized Optimized image
Original 954,2 KB - Optimized 321,4 KB

3.5 How well it is maintained

This plugin is updated on a regular basis & has 6K+ active installs with a 4-star rating.

3.6 Limitations

Ewww Image Optimizer Cloud does not provide a free account, you need to sign up for a plan to test it.

3.7 Pricing

Ewww Image Optimizer Cloud charges per image you optimize, thumbnails included. They have a start fee, that for the monthly plan, for example, is $0.99, and $0.003 for every image you compress. Upon registration, you receive 500 free credits (images to compress).
Pricing plan EWWW Image Optimizer eww_pricing.png

Conclusions

From the quality point of view, all plugins do a great job and you cannot tell the difference between the original and the optimized versions.

In terms of compression, ShortPixel does a great job, reducing the images by more than 80%. Imagify and Ewww Image Optimizer Cloud do a good job too, reducing the images with 60-70%.

Shortpixel and Imagify keep backups until you delete them, Ewww Image Optimizer Cloud only keeps backups for 30 days.

Rather than charging by the number of images like ShortPixel and Ewww Image Optimizer Cloud, Imagify charges by the aggregate file size of all the files you optimize.

All the three plugins offer the same features for both free and paid plans, they only differ in the number of images you can optimize, with Imagify having a limit of 2MB per image on the free plan.

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