Hello, You can do this in 2 ways: # '''Use a file manager app to navigate to your html file and open it.''' Android will ask you which application you want to use to open the file. Choose Firefox and the html file will open. If android doesn't ask which application to use then see the instructions [http://blog.laptopmag.com/how-to-change-default-apps-in-android here] to reset your default application setting. # '''Type the file path directly into the Firefox URL bar.''' The path will have a format something like the following: file:///storage/extSdCard/testpage.html I hope that helps. Let me know if not. Also I notice that you are using Firefox v21. This is now an outdated version. To get the latest security updates I suggest installing the latest version from the Google Play store (v24).