There are many types of paper and paper-size to choose from when printing a paper book. The same myriad of choices applies to digital books except instead of texture and paper-weight, we’re concerned with what device and software the reader may choose to read your book.
If I had all the time in the world and I was producing a fairly simple digital book which didn’t require format specific features I suggest ensuring my digital book was produced in all of these formats:
- epub – an open format which means it will hopefully be around for years to come. An epub file will open in many ebook reader software and hardware such as an iPad or Android device. You can choose epub 2 or epub 3 depending on your target audience – stick with epub 2 for the widest support.
- Amazon kindle format (mobi and kf8) – because amazon rules the market it makes sense to ensure it works on both the kindle software and the kindle device
- Adobe PDF – Almost every device on the planet will open a PDF file so its a safe bet and is also open (see point 1). Further-more PDF is built to handle print, which could be a useful feature for some readers
- Apple ibook (IBA) – if I wanted to sell via the apple marketplace then i’d want to use their format.
Tip: if I was to distribute any of my own books I’d plump for giving ALL of the above to the reader in one bundle. This way they get the choice of their preferred format. I guess an issue for a small number of readers is they’ll receive a zipped bundle and have no clue what to do next. I didn’t say it was fool-proof.
Why is there more than one format I hear you cry? The market for selling ebooks is fierce and each major provider wants you to lock-in to their ecosystem, hence a fragmented market and a high number of file formats.
The key to producing our book fairly painlessly for each format is to plan early and use a workflow that doesn’t rely on any one particular format. The nerds of this world call this being ‘device agnostic’. Essentially write the book using whatever your preferred writing tool is and then have a workflow that makes it straight forward to produce for the context and constraints you have.
If I wanted to sell my digital book and I happened to know that all my potential customers used Amazon then I would likely produce this format first. If I wanted the book to open in say five years time I’d go for epub and PDF.
A final word on file format features
At the time of writing in early 2014, the format with the most advanced features that are implemented by a reading device is the apple ibooks format. It has some pretty impressive features for adding interactivity that may be essential for the success of our book. In which case your workflow for ibooks will split off and tackle those issues. Just be careful that you don’t go so far down that road that you can’t make a good experience for the other hobbled formats. By this i mean that readers and/or software for displaying epub, kindle and PDF don’t yet support any of the advanced feature support you’d like. Things change with each new reader software release though so the future could brighten up any day. If you need to use a feature e.g. video support, check if its supported in your primary testing kit.