Exporting InDesign file for Apple iOS Retina Displays?

[kcrossley]

What's the proper way to export an InDesign CC v15.1.2 file so that it accommodates iOS devices? Although I have my file size set to 250 x 300 pixels, when I export the file using 144 PPI (Retina Resolution) the file dimensions double to 500 x 600 pixels. What am I doing wrong?

Thanks!

[BobLevine]

Export it to what?

[kcrossley]

Sorry, export it to .jpg.

[rob day]

Although I have my file size set to 250 x 300 pixels, when I export the file using 144 PPI (Retina Resolution) the file dimensions double to 500 x 600 pixels

If you want the exported JPEG to have a matching 250px x 300px dimensions set the export Resolution to 72ppi.

[kcrossley]

Yeah, but aren't Retina displays 144 PPI?

[Test Screen Name]

The ppi is irrelevant though. All ppi does is hint a size for printing. On all other cases it's nothing. Your design seems very small though, but it does depend what it is. 

[rob day]

The display resolution depends on the device and its physical dimensions. Here’s an iPhone resolution chart:

https://www.paintcodeapp.com/news/ultimate-guide-to-iphone-resolutions

Most HTML pages are responsive to the device, so in general you want a large enough pixel dimension so that when the image is fit into the available space it is sampled down.