Image Optimizer – WordPress plugin Free download

Click to Download Image Optimizer


This plugin allows you to optimize and resize new and existing WordPress image uploads through Image Optimizer’s API. Both lossless and intelligent lossy optimization modes are supported. Supported filetypes are JPEG, PNG and GIF (including animated GIF). Maximum filesize limit is 32 MB. Even when using’s lossy optimization, our system goes the extra mile to ensure that the results are of high quality, every time. You can just install the plugin and stop worrying.
For more details, including detailed documentation and plans and pricing, please visit

Get your FREE account with us, or a subscription starting from just USD $5 per month

Sign up for your FREE Account and try out our plugin with and the rest of our features now, including:

100MB of free testing quota
API Access, with dozens of ready-to-use libraries and modules
Web Interface PRO with Image Resizing and sync-to-Dropbox
URL Paster
Page Cruncher
Optimization Stats and History
…and more.

Quick start tutorial:

About the plugin

You can use your API key and secret on as many sites/blogs as you like. We have no per-site license.
All images uploaded throught the media uploader are optimized on-the-fly. All generated thumbnails are optimized too.
The main image upload can be optionally resized – this is useful for preventing user uploads with unnecessarily large dimensions. You can specify the maximum width and/or height in>Settings.
When restricting the maximum dimensions of the main image using the resizing feature, the resulting image is enhanced using various advanced techniques, to help prevent downsample artifacts and “haloing” and produce a sharper result.
You can optionally preserve one or more of the Date, Copyright, Geotag, Orientation, Profile EXIF metadata tags.
Images can be automatically oriented according to their EXIF Orientation value – no need to manually rotate images.
All images already present in the media library can be optimized individually, or using the Bulk Action menu “Krak ’em all” feature.
This plugin does not require any root or command-line access. No compilation and installation of any binaries is necessary.
All optimization is carried out by sending images to’s infrastructure, and pulling the optimized files to your WordPress installation.
To use this plugin, you must obtain a full API key and secret from Our free account comes with a limited quota for testing our premium features, including this plugin.
Works great with WPEngine hosted blogs, including the staging area.
Since version 1.0.4, the plugin will work with local WordPress installations; the client site does not need to be published on the web.

????? Excellent Option for Image Optimization
“The real power of Kraken is their “intelligent lossy” optimization. I use it on all my sites and have never once needed to roll back an image because of too much quality degredation. While I hope to see some more advanced settings added to the WordPress plugin in the future, it is a perfect solution as is.” – collin

????? Quality results, quality service
“The plugin works really well and effortlessly, and the support is prompt, thoughtful, and thorough. I’m hooked.” — illustrata

????? Optimize according to Google Pagespeed
“Kraken was instrumental in optimizing images to comply with Google’s Pagespeed analyzing tool. Our travel blog now sports Google’s ‘mobile friendly’ tag for mobile searches” — Walter Schaerer

????? Perfect solution to speed up site!
“I love this plugin! All the questions I had are quickly responded to and I see a huge saving with image size without losing the quality. I highly recommend this plugin!” — ezone69

Once you have obtained your credentials, from your WordPress admin, go to the settings page. The from there you can enter your API credentials, and select your optimization preferences. Once you have done this, click on Save. If everything is in order, it will simply say “settings saved” and give you a reassuring green tick that your credentials are valid. You can now start optimizing images from within Media Library. Any image you upload from now on, through any of the media upload screens will be optimized on-the-fly by

For advanced users, there is a third party WordPress Command Line Interface (CLI) tool to allow image optimization from the command line, or by using cron. For details, visit:

Please send bug reports, problems, feature requests and so on to support (at) Kraken dot io, or directly to the author of this plugin.

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Notes and Incompatible plugins

If you use the WP Super Cache plugin, you must disable the plugin prior to performing any image optimization, as it is known to cause strange and buggy behaviour with the Image Optimizer plugin.

Any Questions?

We love to hear from you! Just shoot an email to support (at) kraken dot io and let’s talk.


This screenshot shows the Settings page. You must enter your credentials, and select your optimization mode from there, then hit save. Advanced options are also available.
This screenshot shows the two columns added by Image Optimizer: original image and Kraked size, as well as the new Optimize This Image button which is present for images which already exist in your media library. Stats and optimization type are shown for optimized images.
This screenshot shows the bulk optimizer aka the “Krak ’em all” feature which appears as an overlay.


To install the Kraken WordPress Plugin:

Upload kraken.php to the /wp-content/plugins/ directory
Activate the plugin through the ‘Plugins’ menu in WordPress
Enter your API key and secret into the new Settings section of Settings->Media.
Any images you upload from now on using WordPress’s Media Upload will be optimized according to your settings. Auto-generated thumbnails will also be optimized.
Images already present can be optimized from within the Media Library.


Can I test the plugin before I purchase an account from

Yes you can. All of our plans require that you first create your free account. No credit card is required, and we give you free testing quota of 50 MB, with which you can test all the features we offer, including this plugin.

Additionally, if you would like to test the performance and results of Image Optimizer, you can try the free Web Interface at which does not require any registration.

Where can I purchase an API key and secret?

From our plans page, right here. In addition to being able to use our WordPress Plugin, you can also use the API in your own applications, and take advantage of our Web Interface PRO feature (and much more!) for as little as USD $5 per month.

Will the optimized images remain on my blog if I uninstall the plugin?

Yes, of course they will. Our plugin simply replaces the image files on your blog with the ones optimized by us.

Where can I find the option to optimize my Media Libary images?

You will need to switch the Media Library from the Grid view to the List view. In the “Kraked Size” column, you will then see the “Optimize This Image” button for unoptimized images, or the results of the optimization where the image has already been optimized by our plugin.

What is the difference between and other plugins such as Optimus, EWWW, WP Smush, Imagify and TinyPNG/TinyJPG?’s service emphasizes finding the precise balance between image quality and file size reduction. Our API utilizes various mechanisms for ensuring that the result cannot be distinguished from the original by the human eye, even upon close inspection. If want to get the greatest possible savings without ever having to check the optimized image against the original, this is the plugin for you.


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