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Asked: 2026-06-08T18:13:15+00:00

I have a simple question for anyone who knows the answer to this… I

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I have a simple question for anyone who knows the answer to this… I am making a social photo sharing app and I want to save a large enough image in the app so that it can be used in a full screen website app moving forward. Think…Facebook.

I’ve been playing around with JPEG compression in iOS and also testing sizes and quality with Photoshop CS5. I get really different results with these two. In photoshop, even at high compression, the image is quite clear and retains lots of detail. In iOS, once the compression dips below about 0.5 it looks horrible and blocky. It almost seems like there’s a point where the image quality just dips after a certain magic compression number.

With photoshop, I use the “Save for Web” option and with iOS I am using UIImageJPEGRepresentation(image, 0.6). Is there a huge difference in these two? Aren’t all JPEGs use the same kind of compression?

I am really not that informed in this world of image processing. Can anyone advice me on what is a good way to have images compressed to a level that preserves quality and stay bandwidth friendly? I want my images to stay about 1280px in length.

Any advice on this or smarter ways to move JPEGS over the network is welcomed. Thank you.

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1 Answer

  1. Editorial Team

    If your app is producing images from an iOS device, you should continue to use UIImageJPEGRepresentation. I don’t think it’s productive comparing the UIKit JPEG compression to Photoshop’s.

    I would find a JPEG compression level you’re happy with using the available UIKit APIs and go with that. When you’re serving up 30+million images a second it might be worth looking at optimisations but until then leave it to UIKit.

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