Whenever we download any PDF file using Internet Explorer or Firefox then the PDF file directly opens inside the browser and we start reading directly from our browsers. ePub is a famous open source file format for eBooks but at times it isn’t supported by most of the browsers. Once you install ePUBReader add-on for firefox then even the ePub files when download using firefox directly open inside the browser instead of you being asked to save them somewhere. If you have already download many ePub files and want to read them then you can read them from Firefox once this is installed. All that you need to do is open those files using Firefox and you are good to go.
All that this add-on does is uncompress the zipped ePub compression and display the necessary file contents via Firefox browser. Remember that all the eBooks will be directly saved in your Firefox profile under a particular sub directory.
Do read our complete guide to ePub file format.