iTunes Connect Error: “Upload Aborted or Timed Out.” when uploading app’s screenshots

When I first saw “Upload Aborted or Timed Out.” I was trying to replace a screenshot for Divine Office Mac on the iTunes Connect interface for the Mac App Store. But googling around I learned this also applies to iPad and iPhone apps. Here is how I solved the issue.

After trying the usual stuff (log out, restart, use chrome, use another copy of the file, select the file without using the search box in the open window…) I gave up thinking it must have been an issue on Apple’s side and that perhaps in a few days it would get corrected. I was wrong!

This problem occurs with all files over about 1 megabyte. Apple recommends using high quality PNG files, didn’t it occur to them that a 1280×800 pixels PNG depicting a Mac App would easily get over 1MB?

Well here is the solution: save your art in JPEG format. Even at maximum quality (using the “Save for Web” feature from Adobe Photoshop), these will hardly get over 1MB in size.