The ePub Viewer is a lightweight, simple, yet effective way to read ePubs on your browsers. You don't need to go through any extra setup. The extension is available for both Chrome and Firefox.

This extension adds a context menu item to the browser link context. It is possible to open and render ePubs using this Viewer.  The ePub Reader extension can be used to open ePubs in a new tab in the browser. You can also change the font size and family from the left side panel.

The extension displays the table of contents (ToC) to help you jump to the desired chapter and stores the current page number and the book URL in the address bar.

Notes:

. The ePub Viewer uses the "Reader View" interface.