Thursday, September 2, 2010

Reading Web Pages From the Android SD Card

Android 1.6 (Donut) tries to make it impossible to read web pages from the SD memory card. Fortunately there is a flaw in their security that lets a user create a specially formatted URL that allows access. This technique may work for other versions of Android but I've only tested it on 1.6.

This is an easy hack. The only skill required is the ability to drag and drop files from the computer to the phone and to connect to this web page via the Android.


For the sake of simplicity the Android based phone is just going to be called the Android. It reads easier.

Local files are the files on the Android SD card. Any references to "the card" mean the Android SD card.

The Desktop is the computer that will be used to edit files and drag and drop the files to and from the Android.

"The browser" is the browser on the Android.


A web page is created on a computer and moved to an arbitrary, but known spot on the Android SD card. A special URL is entered in the Android browser which points to the page. The page is made into a book mark by bypassing the bookmark editor. The web page can then be edited to point to any other location on the SD card.

The Direct Way

This way is direct, but it involves a bit of typing on the Android keyboard. Most people find the longer way easier to get correct.

Put a web page the SD card. This example will use the file webpages/index.html.

Open the browser and type in the URL content://

If index.html shows up in the browser, go to the section "Saving as a Book Mark". If not, check the URL spelling and file location. If the problem can't be solved, use the longer way.

The Longer But Less Fussy Way

This way requires creating a web page on the desktop and the ability to drag a file from the desktop to the Android.

Open an editor ("notepad" will do) and paste the following text:

<title>Found the sd card!</title>
<h1>It worked!</h1>
<li><a href="content://">Self reference.</a></li>
<li><a href="webpages/index.html">Relative links work also.</a></li>
<li><a href="">An external link.</a></li>

Save the file as "foo.html". This is just a temporary file and the name has to be "foo.html" or the rest of the steps won't work.

Copy foo.html to the top level directory of the SD card.

Unhook the Android from the Desktop.

Connect to this blog entry via the Android browser and click on this URL. foo.html should be displayed in the browser.

Saving the Bookmark

While display the web page in the browser, press the menu key. Select "Bookmarks". Select "History". Select "Today". Find the entry for "Found the SD Card!" and click on the star symbol on the right. The bookmark will be added to the browser with no further intervention.

Do not use the "Edit bookmark" option. Just opening the book mark editor with this book mark may corrupt the link and it will stop working.

Changing the Name of the Bookmark

Since the bookmark can't be directly edited, some cleverness is required to move the SD web page and/or change the name of the bookmark.

First create a new web page and install it on the SD card in any arbitrary folder. Edit foo.html and add a link to the new page relative to this page. Bring up foo.html via the previous book mark. Click on the link to the new page. Bookmark the new file.

Once the new page is safely bookmarked, foo.html and it's bookmark can be deleted.


The one quirk that hasn't been figured out is how to jump to the middle of a local web page. Links such as bar.html work fine. Links such as bar.html#middle give an error.

1 comment:

Neil Stoker said...

There *may* be a simpler way...

Perhaps it is something which only works on the HTC Hero, but I discovered that if I created a URL directly in the address bar of the phone's browser in the form shown below then it would work fine:


e.g. file://sdcard/downloads/MyFolder/index.html

If you combine this with using WGET to obtain your html files and set option -k then it will make the links work locally for the html files you've downloaded (and thus when you move them to your phone they'll still work since they're made into relative links)
It's handy for things like online tutorials/manuals you might wish to browse on the Tube!