What resolution should my iPhone App Icon be?

Question

What image resolution can/should be used for the icon.png file for an iPhone app? I know the size is 57 x 57 but what about the resolution?

Answer 1

Here is the link to Apple guidelines, with the sizes for iPad, iPhone retina, etc:

https://developer.apple.com/library/ios/documentation/userexperience/conceptual/mobilehig/AppIcons.html#//apple_ref/doc/uid/TP40006556-CH19-SW1

The "resolution" matters, but don't confuse "resolution" with dpi. Dpi is a measure used for printing, it means "dots per inch". It works like this: if you have an image of 100 x 100 saved at 100dpi, it will measure on paper exactly 1 inch (100 pixels per inch).

The dpi for the icons doesn't really matter, as they are intended for screen display only, not for printing.

It is customary to save images as 72dpi - the so called "screen resolution", because the old 14'' monitors (remember those?) could only display a maximum of 72 pixels per every inch of screen. This is no longer true, especially for the "retina" display of the iPhone. It has a much denser screen resolution, it can show much more pixels in a single inch than the older models of the iPhone. This is why you have to save 2 icons: one for retina display at 114 x 114 pixels, and another for the older iPhones, at 57 x 57. Again, the dpi doesn't matter, because whatever dpi you choose, the number of pixels on your image does not change: it would always have exactly 12,996 pixels (114 x 144).

Answer 2

I only want to say that the DPI (or resolution) is a value that only makes sense when an image is printed. The DPI acronym stands for Dots Per Inch, and it only tells the printer to draw that specific number of pixels by inch of paper. While working on screen devices, the DPI isn't important at all.

Answer 3

57x57, as said.

You can chosse by code if let Apple to add the "shiny effect" or if you'll do (or not) it by yourself

Answer 4

The iPhone 3GS and prior display is 163dpi, so if you intend to create icons that are of a particular size relative to how they are shown, that should give you enough information. Note that the icon must be 57x57 pixels to be shown at that dpi.

The iPhone 4 and later and the fourth generation iPod touch and later have 326 dpi displays, and the icon must be 114x114 dpi to be shown at that dpi.

Answer 5

57 x 57 and Apple takes care of the rest. Apple suggests that you have larger, more detailed graphics for, in the event, that your app gets selected as a feature app.

Answer 6

If creating new images for the iPhone work with the image size in pixels i.e. 57 x 57 for icons. If you work with image sizes set in millimetres or inches, you'll find that 10mm on your monitor equates to only 4.4mm on the iPhone. The iPhone resolution is 163ppi which is over twice (2.25) the 72dpi resolution of a normal monitor. There is another good reason for the question, in that you may need to provide larger images for marketing (websites, blogs, banner ads, or even printed material) requiring zoomed in images that remain super sharp. In these general wider use cases I prefer to work at 300 dpi at the largest target size and then resize/resample image and resolution when done.

Answer 7

I have had the best luck submitting to the App Store with 72dip, 57x57 icons.

Answer 8

Resolution only matters when you are trying to match the size of an image across multiple devices (print, screen, etc)

App icons are always 57x57 and will display without any scaling thus resolution doesn't matter (you could save it as 72dpi, 65535dpi or missing the dpi metadata entirely--SpringBoard won't care and will draw it the same in all three cases)