Web Interface — File Uploader


Support Kraken for as little as $5/mo and get access to the Web Interface PRO. Already have an account? Log in here.
Web Interface PRO comes with increased maximum file size (10MB), additional image sources, cloud storage and image resizing option.

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

Click to upload or drop your images here

File NameOriginal SizeKraked SizeSavings% Savings

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
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