App Press Documentation

Learn how to build mobile apps without writing code.

Optimizing Images

When building an app in App Press, it’s important to understand how image size will affect your app's functionality. Using clear, high-quality images is important, but it’s equally important to keep the file size as small as possible.

A PNG allows for transparencies, but the file size tends to be larger than a JPG. You can also improve loading times by editing your images to match the width of the screen you’re building, instead of scaling down a huge image.

Images in your app will automatically scale to fit the device it's being viewed on. For example, if you build for the iPhone 5/5s/6/6s/6+/6s+ layout, the layout in the editor will be the dimensions for the iPhone 5. If someone views your app on an iPhone 6+, the images and content will scale up. The same is true of Android layouts.

App Press Now will display the full resolution of each image used in the design. Larger file sizes increase the loading time on screen. This means a white flash might appear between app screens as App Press Now takes a second to load and display the images.

This behavior is not final and will change once you preview your app through a share link, or once the final version of your project is published. If you're using an image as the background of your layout, you can make the flash less noticeable by changing the background color of the screen to be closer to the color of the image. For example, if you have a black and white image as the background, make the layout background black.

When your project is previewed though a share link or downloaded from stores, it will be optimized to process images depending on the device use to view the app, reducing the load time of every image. We recommend you preview your app both through App Press Now and via share link, to observe differences between the two experiences.

Last Updated:
May 11, 2016