title_body: Choosing the right dimensions for ePub I am preparing book in Indesign for an eventual ePub export. My page dimensions are:
  
  Width 768 px
  Height 1024 px
  Orientation portrait
  Margins 0 px (since iBooks provides its own margins by default)
  
  I added a cover image with the dimensions 800 px by 600 px. This shows perfectly as expected on my iPad. However, when viewing this ePub in iBooks on my Mac, the image splits across two pages. How can I make the image stay within a single page regardless of the device screen size? On my iPad, the image size remains constant no matter how many times I resize the font.
  
  Also, is there any software one could use to emulate the various devices and their screen sizes for a finished ePub? I am far from able to afford every single reading device there is!
upvoted_answer: First, you are way behind the current standard. 
  
  Most (if not all)  ebook distributors are requiring high resolution graphics for cover images. (a Minimum of 1500 pix or 2000 pix for width). This has been true for at least the last 2 years. 
  
  It's true that some of the smaller devices will display only 600x800, but all distributors recognized early on that it's easier to require a high resolution cover graphic and then downconvert rather than accept smaller graphics which can't be converted to the newer screens. 
  
  Second, I'm assuming you are not using Indesign for a Fixed Layout. Fixed layout requires you to set dimensions etc, but this is NOT epub. Epub is more flexible for a variety of standards. That indeed is the point. 
  
  Amazon (which doesn't accept epub but lets you convert from epub to a Kindle format) has a tool called Kindle Previewer which also lets you emulate the various Amazon devices. http://www.amazon.com/gp/feature.html/ref=amb_link_359603222_5?ie=UTF8&amp;docId=1000765261
  
  I found that on Chrome there is an extension called "Screen Resolution Tester" which lets you simulate various display sizes https://chrome.google.com/webstore/detail/screen-resolution-tester/bnbpeddmakpmblddofjnoghpjminhjph?hl=en
  
  You can also check this reference guide for screen sizes. http://mydevice.io/devices/
  
  This should get you started. I would start by testing dimensions for oldest Amazon Kindle Fire, ipad 1 or 2, ipad 3, the 7 inch ipad, iphone, Galaxy Tab 7 and 10.