Web Interface — File Uploader

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Kraken PRO comes with: 16MB Max File Size API Access Additional Image Sources WP Plugin and more!

URL Paster and Page Cruncher
are available in Kraken PRO
help me choose
Don't resize
more information
Image Resizing
is available in Kraken PRO

Click to upload or drop individual images here

 File NameOriginal SizeKraked SizeSavings% Savings
- OR -

Here you can upload ZIP, RAR or TAR archive containing your images (up to 1 GB).
Kraken will unpack it, optimize all the images and you'll be able to download the entire archive back with folder structure maintainted.

Attention: The technologies employed by our File Uploader interface are not available within your browser environment. We decided to prioritize support for modern browsers, adding in support for older browsers later. In the meantime, we recommend you download Google Chrome or Mozilla Firefox, or make use of URL Paster or Page Cruncher until we finalize support for your browser.

Optimized images are available for download for 12 hours. PRO users can access their images at any time via Kraken Cloud.
Free Web Interface has a file size limit of 1MB.

Image Optimization Mode

Kraken gives you two options which differ in terms of optimization level and image quality. Both modes are a world ahead of other tools - the only thing you have to do is to decide if you want to sacrifice image quality and how much you wish to optimize your images.


This mode will push your images to the extreme without changing a single pixel. Lossless option is perfect when image quality is the most important factor. Keep in mind that this mode is more time consuming.


When you decide to sacrifice just a small amount of image quality (unnoticeable to the human eye), you will be able to save up to 90% (!) of the initial file weight. Lossy optimization will give you outstanding results with just a fraction of image quality loss.

Remember - since outcome is always file-dependent, sometimes you won't be able to tell the difference between images kraked with "lossless" and "lossy" option.

Image Resizing

When you need to generate sets of images in different sizes or dimensions, our easy-to-use image resizing interface has you covered. Just specify your required dimensions and pick one of several strategies for resizing your images, prior to optimization:

ExactResize to exact width and height. Aspect ratio will not be maintained
FitThis option will crop and resize your images to fit the desired width and height
PortraitExact height will be set, width will be adjusted according to aspect ratio
LandscapeExact width will be set, height will be adjusted according to aspect ratio
CropThis option will crop your images to the exact size you specify with no distortion
SquareThis strategy will first crop the image by its shorter dimension to make it a square, then resize it to the specified size
AutoThe best strategy (portrait or landscape) will be selected for a given image according to its aspect ratio

Sync optimized files with your Dropbox

Preparing the upload
1. Log into the Dropbox popup which should be visibile now on your screen.
2. In the Dropbox popup select desired location and hit "Save".

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