Tools for Testing Your Ebooks

The ugly non-secret of ebooks is that they look different on all different platforms. Kindle, iBooks, Nook, Kobo and others. If you want to know what your epubs will look like in the wild, I recommend the following tips and (free!) tools. When we test EPUB outputs at PressBooks, we usually go through the testing process in roughly this order, using these tools:

  1. Epubreader (for Firefox)
    epubreader is a Firefox addon, once it’s installed, you can click on an epub file link (for instance in the “export” page of PressBooks) and it’ll open in EPUB reader. If things look OK in EPUB Reader, it’s a good sign that they should look OK elsewhere.
    How to use it: click on an EPUB link in Firefox, it’ll open automatically in EPUBReader.
  2. Adobe Digital Editions
    ADE is Adobe’s free desktop EPUB reader, which will tell you roughly how different systems that use Adobe’s rendering engine will interpret your EPUBs. Adobe’s rendering engine powers Kobo, Nook, and Sony, though none of them renders things exactly as ADE does.
    How to use it: Browse for your file on your desktop, and select “Open With” –> ADE.
  3. Kindle Previewer
    Kindle Previewer converts your EPUB to Amazon format, and it also shows you what your files will look like on the SIX (!!) different Kindle platforms (Kindle Fire, Kindle Touch, Kindle DX, Kindle iPad, Kindle iPhone, Kindle).
    How to use it: Open Kindle Previewer, then File–>Open–>select your EPUB.
  4. iBooks (for iPad/iPod/iPhone)
    iBooks is Apple’s built-in ebook reading app.
    How to use it: The easiest way to check your EPUB is to email the file to yourself, and then click on the file from your iOS device. Your device will ask you what program you’d like to open it in.
  5. Kobo (for iPad/iPod/iPhone)
    Kobo is another common ebook reader, and it’s worth checking out how things look on it.
    How to use it: If you have Kobo installed on your iPhone/iPad, then easiest way to check your EPUB is to email the file to yourself, and then click on the file from your iOS device. Your device will ask you what program you’d like to open it in. Choose Kobo.
  6. Dropbox
    Dropbox is a great tool to let you access files from multiple devices — drop your EPUB file into a folder in dropbox, then you can access it from your iPad, iPhone, Android tablet or phone, and — I presume — your Windows device (haven’t heard of anyone testing on those yet!)
    How to use it: download Dropbox on your computer and all your devices, and make an “EPUB Testing” folder, where you can drop your files.
  7. Epub Validator
    Our last stop is usually EPUB Validator, which is an online tool from IDPF that will “validate” your EPUB — to make sure that the file conforms to the EPUB specifications. EPUB check errors can be obscure, but if something is wrong there, chances are you’ll have problems getting your EPUB into retailers.
    How to use it: go to: and upload your file.

15 thoughts on “Tools for Testing Your Ebooks

  1. Great list. I would add Readium (, the IDPF’s EPUB3 compatible ereader, to the list. It’s the only desktop ereader that can read Fixed Layout EPUB, and it also has the best support for EPUB3 (next to iBooks).

    Note that it currently works only on Google Chrome, not that that’s a big inconvenience.

  2. Oops, one more. I would also add EpubCheck ( as an alternative to EPUB Validator, which although online and easy, is limited to files up to 10Mb. EpubCheck, on which EPUB Validator is based, is run from the command line (which makes it slightly more complicated to use), but is faster because it doesn’t require uploading files anywhere, and has no size limit.

  3. Hugh, excellent article. Very useful. Including the suggestions by Liz Castro (I bought, read and suggest your ebook “EPUB Straight to the point”). I’d like to propose, for an upcoming article, a similar analysis, more focused on validators, for ONIX 3.0 files. Is it possible? Thanks in advance.

  4. Here is a free ebook tool for you.

    You can easily convert your ebook from epub to pdf,epub to mobi, epub to kindle, etc.

    Free Online Converter / EPUB Converter

    It provides you with the best mobi to epub converting experience.

  5. Now, I know that the Kobo eReader is an e-book reader produced by Toronto-based company Kobo Inc. Thank you for sharing this really recommended tips and free tools. Keep posting a very helpful information.

  6. Do you have any recommendations for a proofreader (me) checking a file for a client? Typically they prefer that you mark errors, not just make corrections. What is the most effective way to mark errors? I’m used to working with PDFs that I can mark up in a variety of ways.

    Thanks so much for the list! I’m going to give this a run-through.

  7. I was more than happy to find this page. I wanted to thank you for ones time for this fantastic
    read!! I definitely enjoyed every little bit of it
    and i also have you saved as a favorite to see new information in your website.

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