Help for BSON Books Viewer

To use the BSON Books Viewer, the first step is to download ebook files. The Viewer employs a specific method of download called "import" that directly saves the ebook contents into a database located on your computers or mobile devices. The Viewer can then display ebook contents from the local database and let you bookmark, highlight, annotate and search even without internet connection.

Download eBook Files

  1. For Style s (recommended for smartphones and small tablets), click on Menu at the top left to bring up a menu. In the menu, click on Portal to visit a portal page where you can access over a thousand of BSON books.
    For Style L (recomended for larger devices), click on Portal at the top left to visit the portal page.
  2. Select a book via category, search, or featured titles in the portal page.
  3. From the information page of the selected book, click .

If successful, the book will show up in the Viewer after the importing process is complete.

Limitation: Laptops can process all of our BSON books even for the file size as large as 30 MB. Smartphones and tablets impose a certain limit that increases with larger storage. For a device with 64 GB storage, the limit is about 5 MB per book file. Currently, all major browsers have implemented the functions required by the Viewer to read BSON books offline. A notable exception is Apple's mobile Safari which works on iOS 13, but not iSO 14. In the latter case, you may use other browsers (e.g., Chrome, Forefox, or Edge) on iPhones.

Nevigation Within an eBook Page

"eBook Page" and "Screen Page"

The "eBook page", or "ePage" in short, refers to a document equivalent to an article on a website. It is typically a chapter or a section of a book. An ePage may be many times longer than a screen. This presents a difficulty for nevigation within an ePage, especially on smartphones. Traditionally, most eBook readers (viewers) divide an eBook page into "screen pages" with height about the same as the screen. A horizontal scroll bar is also added to the bottom for quick access to a particular screen page. Such design usually prevents vertical scrolling that many people prefer.

Apple Books APP has implemented vertical scrolling a few years ago, followed by Amazon Kindle APP in 2019. A vertical scroll bar is added to the right edge, where you can move a small circle to jump to different parts of an eBook (more info). However, either a horizonal or vertical scroll bar takes up the precious space on a small screen. The Viewer uses the following "Web Books Scrolling" to quickly nevigate through an ePage without any scroll bar.

Web Books Scrolling
  1. Swipe to left or right. This will scroll down or up by the height of a screen. In effect, it turns a "screen page."
  2. Tap either right or left edge. This will scroll directly to the part corresponding to the tapped position in the vertical edge of the screen.

The second function is equivalent to moving a vertical scroll bar using a mouse, or to the method employed by Apple Books APP. It is even more convenient. No need to drag the scroll bar. Just tap a position in the vertical edge, you will reach the corresponding part of an ePage (a chapter or section). For instance, tap the upper corner will show the top portion of an ePage. Tap the mid-position of the vertical edge will display the middle portion of an ePage. Tap the bottom corner will reach the last portion immediately. The Web Books Scrolling works on ALL touch devices.


For Style s, clicking Image will display a menu. Click it again to hide the menu. Clicking Image will display table of contents (TOC). Click it again to hide TOC. For Style L, the button Image at the top right lets you change the background color, font size, and library view (tiles or list).

The button Image is for going to the previous ePage. In Stye L, the button Image is for going back to the ePage that links to the current ePage. For Style s, the link "Go Back" in the menu has the same functionality.

Remove Books from Library

Books may be removed from the library only in the list view. For Style s, click on Image will immediately remove the title from the library. For Style L, click Image in front of the title will bring up the "Manage the book" page where you can change the category for the book or remove it from the library.


Double click (using mouse) or double tap (using finger) at the paragraph you wish to bookmark. If successful, a red symbol will appear at the beginning of the paragraph.

Please note that the Viewer does not automatically track which book or where in a book you are reading. You must bookmark to let the Viewer know. If a book is bookmarked, clicking on its thumbnail or title in the library will go to the bookmarked position.

Create Highlights, Notes and Links

For mouse-operated devices, use the mouse to select a text. For touch-capable devices, use long press (tap and hold for about 1 second) to select a text. A menu will appear at the bottom for "highlight", "Note" and "Link".

Edit and Delete

The following background colors are used to distinguish different types of mark-ups: Highlights, Notes, and Links. Clicking on Highlights will bring up the option to delete the highlight. Clicking on Notes to view, edit, or delete the note. Clicking on Links will go directly to the linked Web page on the internet.

Highlights, Notes and Links can also be deleted by clicking "X" in their listing which can be accessed from the button Image in Style L or Image (then "Show Notes") in Style s.

Advanced Search

You can find a phrase or multiple separated words in a single book or the entire library (database) on your reading devices. You can also use wildcard * in search inputs to match any characters. For instance, if you type "she walks * beauty" (NO quotation marks), the Viewer can find the ePage containing the Byron's poem "she walks in beauty".

A search input with the wildcard * will be treated as a phrase, not separated words. Therefore, to find a phrase, simply add the wildcard * at the beginning. Example: typing "lion fox" can find the ePage containing "lion" and "fox" at different locations, but "*lion fox" can only find the ePage with "lion" and "fox" together.

In the matched ePages, the matched words are highlighted. An ePage may contain several matches. Clicking a highlighted match will go to the next match.


The BSON Books Viewer disables the intrinsic zoom function (e.g., by dragging with 2 fingers) to prevent text flowing outside the screen, which would require horizontal scrolling to read the whole line of text. This situation is unacceptable by most users. The Viewer provides its own method to enlarge text and images.


To magnify text, simply change the font size from the setting. In style L, click on Image at the top right. In style s, clicking on Image will display a menu that contains setting.


Double clicks (or taps) on an image will open the image in a new tab (or window) where you may use the intrinsic method to zoom in or out.

Tables and Equations

As mentioned above, our Viewer does not allow horizontal scrolling. This presents a difficulty for small devices to display large tables or long mathematical equations. Our BSON books are specifically designed to make tables and equations horizontally scrollable. [This feature is not complete yet]

Add the Viewer to Home Screen

It is recommended that you add the BSON Books Viewer to the home screen, because it will be displayed in FULL SCREEN (the "APP mode") which has more viewing area than the "Browser mode" that typically displays the Web address. This function is available on most laptops and mobile devices. On Apple's products, however, Safari is the only browser that can add Web APP to home screen. Unfortunately, Safari on mobile iOS 14 does not implement a feature required for offline reading. In this case, you will have to use other browsers such as Google Chrome or Firefox.


Last updated: March 27, 2021