I use Ebook Reader. I attempted to use the download option on the MyBook list (the three dots). The file that came was incompatible with my ebook reader.

It was: Warriors_2_Fire_and_Ice-epub.acsm

I tried renaming the book in various ways such as:

  • Warriors_2_Fire_and_Ice-epub
  • Warriors_2_Fire_and_Ice.epub

However, I couldn't import either of those files into my ebook reader.

The extension .acsm might be the offline extension for ebooks. I thought I had seen it as an epub before.

So if that is the case, can someone advise me on how to convert the downloaded book to a way that I can import it into my ebook reader library?


3 Answers 3


As the answer to Are Google Books DRM protected? explains, ACSM files are DRM-protected, so you can only read them in the Play Books app itself, not in another ebook app. Once you've "pinned" the book and it has downloaded, you can read it offline in the Play Books app.

  • Thanks for the information. I would never have purchased the book if I had known it wasn't possible to read it in my favorite ebook reader. I'll have to study for future reference how to tell which books I'll be able to download to my android to read in my preferred feature reader. The features of the play book reader are not easy on my eyes... not easy for me to use. All the other books I've purchased are in my offline library (the library of my ebook reader). Thanks for clearing this up for me! Commented Jul 25, 2014 at 10:03
  • 1
    That's one of the reasons I don't use Play Books at all. There are plenty of ebook readers available, and many sources of ebooks without DRM (e.g. my library), I prefer to stick wit those. As an author, ebooks I release are not DRM protected (even not on Amazon) for exactly the reason you named: I don't want to restrict my readers on where/how they want to read the books.
    – Izzy
    Commented Jul 25, 2014 at 12:11
  • If it is hard on your eyes, you can change the display settings for reading books in the Play Books app.
    – user373082
    Commented Sep 21, 2022 at 21:24

As mentioned in the other answer, the ACSM files have DRM so one method is to just read in the Play Books app. It sounds like you'd prefer to use another reader though. So, another solution is to remove the DRM using a program I wrote called Knock. This will spit out a DRM-free EPUB or PDF file that you can read in any reader.

  • 1
    In some jurisdictions, this is illegal. Where I live, for example, copying for personal backup, or converting to a format suitable for my device of choice, is legal, but only as long as I do not have to break any kind of copy pretection to do it. Your app may well be legal in other jurisdictions, but I do believe that you should at least point out that in some jurisdictions it may be prohibited.
    – user372918
    Commented Jun 5, 2022 at 4:45

According to the 2nd revision of the OP's question (with copyedit),

This is a clarification of the answer provided by Dan Hulme.

Important components of the answer:

  1. The book is automatically downloaded and readable offline when reading it online.
  2. The download works the ACSM is a package of the download which can be loaded on authorized machines for reading (via authorized readers).

You can get the program for your Mac or Windows at:


For Linux, you have to install Wine and run the Windows Version.

At present, the latest Windows release doesn't work with Linux (Wine) you have to use version ADE17 for Linux:

Install Adobe Digital Editions on Linux

For the Android so far I find:

Aldiko Book Reader

I agree with Izzy's brilliant reflection that in the future I'll have to search for books that don't have this restriction.

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