statushighly stableOSWindows Serverembeddable byC#/F#/VB.NET except .NET CoreREST APIsQuerystring APIweb serverIIScodecsWindows APIsfile sizesdecentperformancegoodcolor profileslimited by windowsbuilt withC#, F#, C++/CLI, C89rendering engineGDI+ (free) / custom (with Performance license)

ImageResizer is the best image server for ASP.NET. It can be dropped into existing apps and works alongside your CMS or existing platform to eliminate manual image tasks, enable fast and adaptive websites, and improve your sales by reducing page load time.


statustechnical previewOSWindows, Linux, Macembeddable byall C compatible languagesREST APIsJSON API, Querystring APIweb serverbuilt-incodecsOSS+customfile sizesworld-classperformanceunparalleledcolor profilescorrectbuilt withRust, C11, C++rendering enginecustom

Imageflow is in development, but you can download a working preview and give us feedback.

  • libimageflow.dll makes a cross-platform ImageResizer library possible.
  • imageflow_server is a RESTful image server and faster ImageResizer replacement.
  • imageflow_tool is perfect for batch processing - up to 17x faster than ImageMagick.

Your server can prepare images 5,000 50,000 times faster than you. Let it compress more than your HTML.

  • <div class="container">
  •   <img src="img.jpg?" />
  • </div>
cable car

Add commands to image URLs to get altered versions in milliseconds. Save for Web is dead; embrace the responsive web.

Create images that impress and inspire

ImageResizer provides a comprehensive set of photography tools, from powerfully simple one-command adjustments, such as white balance correction and noise removal, to cutting-edge advanced controls, such as red-eye correction, object removal, and seam carving. Have your server deliver final images to the browser in milliseconds.

Here's a review of basic commands and here's a more comprehensive rundown with advanced features.

Don't Believe Us?

ImageResizer is trusted by small businesses and Fortune 500 companies alike. We're proud to let our customer satisfaction and our product speak for themselves.

Explore Our Site


Resizer 4.1.9 - Jun-22-2017

Important fix for constant CPU use

Resizer 4.1.8 - Jun-17-2017

2 bug fixes

Resizer 4.1.7 - Jun-6-2017

166 commits

Resizer 4.0.5 - Jan-31-2016

3 bug fixes

Resizer 4.0.4 - Oct 25 2015

Major release with security and massive performance improvements

Highlights of ImageResizer v4

Highlights of ImageResizer v4


More Open-Source Products from Imazen


Slimmage allows CSS, not HTML, to control which image size is downloaded. Creating responsive images has never been so easy.


Studio JS

Studio JS is a rapidly growing collection of jQuery plugins for image cropping, resizing, and editing. Click here for a live demo.



KeyHub is an open source license key management system.



Repositext is a collection of components and recipes to create your ideal large-scale publishing workflow.

Ruby C

Hardwired CMS

Hardwired is the coder's ideal CMS. Tiny, unrestrictive, managed with Git and a text editor. Used by all Imazen sites.

Ruby Sinatra


Reunion is both a library and a local webapp for repeatable accounting. Do your accounting in a single day.

Ruby Sinatra