Mac App Store

Mac App Store is the simplest way to find and download apps for your Mac.

To download Duplex from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.


By Moople

Open the Mac App Store to buy and download apps.


Duplex is a very simple utility to help designers and developers quickly create upscaled images for use on HiDpi or retina displays.

What is Duplex?
Duplex is a very simple Macintosh application that handles batch scaling of images. The main purpose of Duplex was to provide a quick way for designers or developers to produce assets to improve the look of their existing sites on retina displays.

Why do I need Duplex?
If you have a site that doesn't look great on a retina/HiDPI display because your image assets are too small (and you don’t have higher resolution originals), Duplex can help. Duplex does it’s best to produce upscaled double-sized images from your originals which you can then run at the intended size, often with great results. Duplex can also take your high resolution images and scale them to half size for serving to non-retina displays.

What kind of image work best?
Duplex works really well with photographic images, complex UI assets (inc gradients), and UI chrome like buttons etc. Duplex’s scaling algorithm minimises bitmap compression artifacts and produces clean as possible versions of your originals. Of course YMMV.

What is it not so good for?
Unfortunately upscaling bitmapped graphics will never produce completely brilliant images. It’s impossible to magically recreate an image twice as big and retain the sharpness of the original. Some images will work better than others, but Duplex struggles most with detailed aliasing such as around text (but you’re not using images for text right? :) )

How does it work?
Simply drag your Jpg or PNG files onto Duplex’s conversion window, choose a home for your new images and Duplex does the rest. Duplex appends @2x to double sized images or @1x to half sized images, allowing you to programmatically serve the appropriate images to standard or retina devices.

How can I use Duplex assets with my site?
There are many ways to add @2x support to your site, but we’re massive fans of - a very simple way to detect and swap out images for higher resolution images if the device supports it. You may also wish to add in a test to check for bandwidth before serving larger images to your users.


Screenshot 1

Customer Reviews

Perfect, Simple and Reliable

At first, I though this app was a bit pricey for how simple it was, but I must say, I have been completely satisfied with this purchase. I am a web developer, and once I got my retina MacBook Pro, I became obsessed with the fact that websites are almost never retina friendly. I deemed to make my sites High Resolution, and up until now, I have been trying to write scripts or find apps to make this process easier. I know there are other apps that do this, but non of them really upscale that well, or are buggy. This sped up my graphics workflow and made me excited to make my sites high res. The time-consuming task is now the easy part.

I found this to be the easiest solution and the customer support is awesome. I wrote about an iron problem with the app, and they resonded in less than an hour.

The app isn't retina freindly as of now, but it's still a VERY good solution to having 1x and 2x graphics for your site development.

No Retina Graphics

I'm flabbergasted that this app doesn't have retina friendly graphics in it's UI. The arrow and radio sliders are standard resolution graphics. Absurd for an app built to be used with and for high resolution screens.

View in Mac App Store
  • $1.99
  • Category: Graphics & Design
  • Released:
  • Version: 1.0
  • Size: 1.2 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.7 or later, 64-bit processor

Customer Ratings

We have not received enough ratings to display an average for the current version of this application.