The new devices also have a HDMI (high-definition multimedia interface) port so the tablets can be connected to high-definition TV sets.

The Kindle Fire tablets now have Microsoft Exchange integration. A new email client offers support for Google's Gmail, Microsoft's Exchange and Hotmail.

The new tablets also have features like X-ray, where information about actors is shown on-screen when a movie is playing. A new feature called FreeTime sets time limits for different types of content activity. For example, the new feature can set the amount of time that kids can play games during a day.

Amazon has also re-priced the original Kindle Fire to $159, with more RAM and a faster processor. The tablet was originally priced at $199.

The first Kindle Fire became Amazon's most successful product, and in its first year the device captured 22 percent of U.S. tablet sales, according to the company.